vendor: add cfssl dependency

This commit is contained in:
George Tankersley
2016-06-29 15:56:16 -07:00
parent 9e45f62fc3
commit 902b9faa6f
64 changed files with 16192 additions and 3 deletions

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Apache License
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http://www.apache.org/licenses/
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This is the really early beginnings of a certificate transparency log
client written in Go, along with a log scanner tool.
You'll need go v1.1 or higher to compile.
# Installation
This go code must be imported into your go workspace before you can
use it, which can be done with:
go get github.com/google/certificate-transparency/go/client
go get github.com/google/certificate-transparency/go/scanner
etc.
# Building the binaries
To compile the log scanner run:
go build github.com/google/certificate-transparency/go/scanner/main/scanner.go
# Contributing
When sending pull requests, please ensure that everything's been run
through ```gofmt``` beforehand so we can keep everything nice and
tidy.

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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package asn1 implements parsing of DER-encoded ASN.1 data structures,
// as defined in ITU-T Rec X.690.
//
// See also ``A Layman's Guide to a Subset of ASN.1, BER, and DER,''
// http://luca.ntop.org/Teaching/Appunti/asn1.html.
//
// START CT CHANGES
// This is a fork of the Go standard library ASN.1 implementation
// (encoding/asn1). The main difference is that this version tries to correct
// for errors (e.g. use of tagPrintableString when the string data is really
// ISO8859-1 - a common error present in many x509 certificates in the wild.)
// END CT CHANGES
package asn1
// ASN.1 is a syntax for specifying abstract objects and BER, DER, PER, XER etc
// are different encoding formats for those objects. Here, we'll be dealing
// with DER, the Distinguished Encoding Rules. DER is used in X.509 because
// it's fast to parse and, unlike BER, has a unique encoding for every object.
// When calculating hashes over objects, it's important that the resulting
// bytes be the same at both ends and DER removes this margin of error.
//
// ASN.1 is very complex and this package doesn't attempt to implement
// everything by any means.
import (
// START CT CHANGES
"errors"
"fmt"
// END CT CHANGES
"math/big"
"reflect"
// START CT CHANGES
"strings"
// END CT CHANGES
"time"
)
// A StructuralError suggests that the ASN.1 data is valid, but the Go type
// which is receiving it doesn't match.
type StructuralError struct {
Msg string
}
func (e StructuralError) Error() string { return "asn1: structure error: " + e.Msg }
// A SyntaxError suggests that the ASN.1 data is invalid.
type SyntaxError struct {
Msg string
}
func (e SyntaxError) Error() string { return "asn1: syntax error: " + e.Msg }
// We start by dealing with each of the primitive types in turn.
// BOOLEAN
func parseBool(bytes []byte) (ret bool, err error) {
if len(bytes) != 1 {
err = SyntaxError{"invalid boolean"}
return
}
// DER demands that "If the encoding represents the boolean value TRUE,
// its single contents octet shall have all eight bits set to one."
// Thus only 0 and 255 are valid encoded values.
switch bytes[0] {
case 0:
ret = false
case 0xff:
ret = true
default:
err = SyntaxError{"invalid boolean"}
}
return
}
// INTEGER
// parseInt64 treats the given bytes as a big-endian, signed integer and
// returns the result.
func parseInt64(bytes []byte) (ret int64, err error) {
if len(bytes) > 8 {
// We'll overflow an int64 in this case.
err = StructuralError{"integer too large"}
return
}
for bytesRead := 0; bytesRead < len(bytes); bytesRead++ {
ret <<= 8
ret |= int64(bytes[bytesRead])
}
// Shift up and down in order to sign extend the result.
ret <<= 64 - uint8(len(bytes))*8
ret >>= 64 - uint8(len(bytes))*8
return
}
// parseInt treats the given bytes as a big-endian, signed integer and returns
// the result.
func parseInt32(bytes []byte) (int32, error) {
ret64, err := parseInt64(bytes)
if err != nil {
return 0, err
}
if ret64 != int64(int32(ret64)) {
return 0, StructuralError{"integer too large"}
}
return int32(ret64), nil
}
var bigOne = big.NewInt(1)
// parseBigInt treats the given bytes as a big-endian, signed integer and returns
// the result.
func parseBigInt(bytes []byte) *big.Int {
ret := new(big.Int)
if len(bytes) > 0 && bytes[0]&0x80 == 0x80 {
// This is a negative number.
notBytes := make([]byte, len(bytes))
for i := range notBytes {
notBytes[i] = ^bytes[i]
}
ret.SetBytes(notBytes)
ret.Add(ret, bigOne)
ret.Neg(ret)
return ret
}
ret.SetBytes(bytes)
return ret
}
// BIT STRING
// BitString is the structure to use when you want an ASN.1 BIT STRING type. A
// bit string is padded up to the nearest byte in memory and the number of
// valid bits is recorded. Padding bits will be zero.
type BitString struct {
Bytes []byte // bits packed into bytes.
BitLength int // length in bits.
}
// At returns the bit at the given index. If the index is out of range it
// returns false.
func (b BitString) At(i int) int {
if i < 0 || i >= b.BitLength {
return 0
}
x := i / 8
y := 7 - uint(i%8)
return int(b.Bytes[x]>>y) & 1
}
// RightAlign returns a slice where the padding bits are at the beginning. The
// slice may share memory with the BitString.
func (b BitString) RightAlign() []byte {
shift := uint(8 - (b.BitLength % 8))
if shift == 8 || len(b.Bytes) == 0 {
return b.Bytes
}
a := make([]byte, len(b.Bytes))
a[0] = b.Bytes[0] >> shift
for i := 1; i < len(b.Bytes); i++ {
a[i] = b.Bytes[i-1] << (8 - shift)
a[i] |= b.Bytes[i] >> shift
}
return a
}
// parseBitString parses an ASN.1 bit string from the given byte slice and returns it.
func parseBitString(bytes []byte) (ret BitString, err error) {
if len(bytes) == 0 {
err = SyntaxError{"zero length BIT STRING"}
return
}
paddingBits := int(bytes[0])
if paddingBits > 7 ||
len(bytes) == 1 && paddingBits > 0 ||
bytes[len(bytes)-1]&((1<<bytes[0])-1) != 0 {
err = SyntaxError{"invalid padding bits in BIT STRING"}
return
}
ret.BitLength = (len(bytes)-1)*8 - paddingBits
ret.Bytes = bytes[1:]
return
}
// OBJECT IDENTIFIER
// An ObjectIdentifier represents an ASN.1 OBJECT IDENTIFIER.
type ObjectIdentifier []int
// Equal reports whether oi and other represent the same identifier.
func (oi ObjectIdentifier) Equal(other ObjectIdentifier) bool {
if len(oi) != len(other) {
return false
}
for i := 0; i < len(oi); i++ {
if oi[i] != other[i] {
return false
}
}
return true
}
// parseObjectIdentifier parses an OBJECT IDENTIFIER from the given bytes and
// returns it. An object identifier is a sequence of variable length integers
// that are assigned in a hierarchy.
func parseObjectIdentifier(bytes []byte) (s []int, err error) {
if len(bytes) == 0 {
err = SyntaxError{"zero length OBJECT IDENTIFIER"}
return
}
// In the worst case, we get two elements from the first byte (which is
// encoded differently) and then every varint is a single byte long.
s = make([]int, len(bytes)+1)
// The first varint is 40*value1 + value2:
// According to this packing, value1 can take the values 0, 1 and 2 only.
// When value1 = 0 or value1 = 1, then value2 is <= 39. When value1 = 2,
// then there are no restrictions on value2.
v, offset, err := parseBase128Int(bytes, 0)
if err != nil {
return
}
if v < 80 {
s[0] = v / 40
s[1] = v % 40
} else {
s[0] = 2
s[1] = v - 80
}
i := 2
for ; offset < len(bytes); i++ {
v, offset, err = parseBase128Int(bytes, offset)
if err != nil {
return
}
s[i] = v
}
s = s[0:i]
return
}
// ENUMERATED
// An Enumerated is represented as a plain int.
type Enumerated int
// FLAG
// A Flag accepts any data and is set to true if present.
type Flag bool
// parseBase128Int parses a base-128 encoded int from the given offset in the
// given byte slice. It returns the value and the new offset.
func parseBase128Int(bytes []byte, initOffset int) (ret, offset int, err error) {
offset = initOffset
for shifted := 0; offset < len(bytes); shifted++ {
if shifted > 4 {
err = StructuralError{"base 128 integer too large"}
return
}
ret <<= 7
b := bytes[offset]
ret |= int(b & 0x7f)
offset++
if b&0x80 == 0 {
return
}
}
err = SyntaxError{"truncated base 128 integer"}
return
}
// UTCTime
func parseUTCTime(bytes []byte) (ret time.Time, err error) {
s := string(bytes)
ret, err = time.Parse("0601021504Z0700", s)
if err != nil {
ret, err = time.Parse("060102150405Z0700", s)
}
if err == nil && ret.Year() >= 2050 {
// UTCTime only encodes times prior to 2050. See https://tools.ietf.org/html/rfc5280#section-4.1.2.5.1
ret = ret.AddDate(-100, 0, 0)
}
return
}
// parseGeneralizedTime parses the GeneralizedTime from the given byte slice
// and returns the resulting time.
func parseGeneralizedTime(bytes []byte) (ret time.Time, err error) {
return time.Parse("20060102150405Z0700", string(bytes))
}
// PrintableString
// parsePrintableString parses a ASN.1 PrintableString from the given byte
// array and returns it.
func parsePrintableString(bytes []byte) (ret string, err error) {
for _, b := range bytes {
if !isPrintable(b) {
err = SyntaxError{"PrintableString contains invalid character"}
return
}
}
ret = string(bytes)
return
}
// isPrintable returns true iff the given b is in the ASN.1 PrintableString set.
func isPrintable(b byte) bool {
return 'a' <= b && b <= 'z' ||
'A' <= b && b <= 'Z' ||
'0' <= b && b <= '9' ||
'\'' <= b && b <= ')' ||
'+' <= b && b <= '/' ||
b == ' ' ||
b == ':' ||
b == '=' ||
b == '?' ||
// This is technically not allowed in a PrintableString.
// However, x509 certificates with wildcard strings don't
// always use the correct string type so we permit it.
b == '*'
}
// IA5String
// parseIA5String parses a ASN.1 IA5String (ASCII string) from the given
// byte slice and returns it.
func parseIA5String(bytes []byte) (ret string, err error) {
for _, b := range bytes {
if b >= 0x80 {
err = SyntaxError{"IA5String contains invalid character"}
return
}
}
ret = string(bytes)
return
}
// T61String
// parseT61String parses a ASN.1 T61String (8-bit clean string) from the given
// byte slice and returns it.
func parseT61String(bytes []byte) (ret string, err error) {
return string(bytes), nil
}
// UTF8String
// parseUTF8String parses a ASN.1 UTF8String (raw UTF-8) from the given byte
// array and returns it.
func parseUTF8String(bytes []byte) (ret string, err error) {
return string(bytes), nil
}
// A RawValue represents an undecoded ASN.1 object.
type RawValue struct {
Class, Tag int
IsCompound bool
Bytes []byte
FullBytes []byte // includes the tag and length
}
// RawContent is used to signal that the undecoded, DER data needs to be
// preserved for a struct. To use it, the first field of the struct must have
// this type. It's an error for any of the other fields to have this type.
type RawContent []byte
// Tagging
// parseTagAndLength parses an ASN.1 tag and length pair from the given offset
// into a byte slice. It returns the parsed data and the new offset. SET and
// SET OF (tag 17) are mapped to SEQUENCE and SEQUENCE OF (tag 16) since we
// don't distinguish between ordered and unordered objects in this code.
func parseTagAndLength(bytes []byte, initOffset int) (ret tagAndLength, offset int, err error) {
offset = initOffset
b := bytes[offset]
offset++
ret.class = int(b >> 6)
ret.isCompound = b&0x20 == 0x20
ret.tag = int(b & 0x1f)
// If the bottom five bits are set, then the tag number is actually base 128
// encoded afterwards
if ret.tag == 0x1f {
ret.tag, offset, err = parseBase128Int(bytes, offset)
if err != nil {
return
}
}
if offset >= len(bytes) {
err = SyntaxError{"truncated tag or length"}
return
}
b = bytes[offset]
offset++
if b&0x80 == 0 {
// The length is encoded in the bottom 7 bits.
ret.length = int(b & 0x7f)
} else {
// Bottom 7 bits give the number of length bytes to follow.
numBytes := int(b & 0x7f)
if numBytes == 0 {
err = SyntaxError{"indefinite length found (not DER)"}
return
}
ret.length = 0
for i := 0; i < numBytes; i++ {
if offset >= len(bytes) {
err = SyntaxError{"truncated tag or length"}
return
}
b = bytes[offset]
offset++
if ret.length >= 1<<23 {
// We can't shift ret.length up without
// overflowing.
err = StructuralError{"length too large"}
return
}
ret.length <<= 8
ret.length |= int(b)
if ret.length == 0 {
// DER requires that lengths be minimal.
err = StructuralError{"superfluous leading zeros in length"}
return
}
}
}
return
}
// parseSequenceOf is used for SEQUENCE OF and SET OF values. It tries to parse
// a number of ASN.1 values from the given byte slice and returns them as a
// slice of Go values of the given type.
func parseSequenceOf(bytes []byte, sliceType reflect.Type, elemType reflect.Type) (ret reflect.Value, err error) {
expectedTag, compoundType, ok := getUniversalType(elemType)
if !ok {
err = StructuralError{"unknown Go type for slice"}
return
}
// First we iterate over the input and count the number of elements,
// checking that the types are correct in each case.
numElements := 0
for offset := 0; offset < len(bytes); {
var t tagAndLength
t, offset, err = parseTagAndLength(bytes, offset)
if err != nil {
return
}
// We pretend that GENERAL STRINGs are PRINTABLE STRINGs so
// that a sequence of them can be parsed into a []string.
if t.tag == tagGeneralString {
t.tag = tagPrintableString
}
if t.class != classUniversal || t.isCompound != compoundType || t.tag != expectedTag {
err = StructuralError{"sequence tag mismatch"}
return
}
if invalidLength(offset, t.length, len(bytes)) {
err = SyntaxError{"truncated sequence"}
return
}
offset += t.length
numElements++
}
ret = reflect.MakeSlice(sliceType, numElements, numElements)
params := fieldParameters{}
offset := 0
for i := 0; i < numElements; i++ {
offset, err = parseField(ret.Index(i), bytes, offset, params)
if err != nil {
return
}
}
return
}
var (
bitStringType = reflect.TypeOf(BitString{})
objectIdentifierType = reflect.TypeOf(ObjectIdentifier{})
enumeratedType = reflect.TypeOf(Enumerated(0))
flagType = reflect.TypeOf(Flag(false))
timeType = reflect.TypeOf(time.Time{})
rawValueType = reflect.TypeOf(RawValue{})
rawContentsType = reflect.TypeOf(RawContent(nil))
bigIntType = reflect.TypeOf(new(big.Int))
)
// invalidLength returns true iff offset + length > sliceLength, or if the
// addition would overflow.
func invalidLength(offset, length, sliceLength int) bool {
return offset+length < offset || offset+length > sliceLength
}
// START CT CHANGES
// Tests whether the data in |bytes| would be a valid ISO8859-1 string.
// Clearly, a sequence of bytes comprised solely of valid ISO8859-1
// codepoints does not imply that the encoding MUST be ISO8859-1, rather that
// you would not encounter an error trying to interpret the data as such.
func couldBeISO8859_1(bytes []byte) bool {
for _, b := range bytes {
if b < 0x20 || (b >= 0x7F && b < 0xA0) {
return false
}
}
return true
}
// Checks whether the data in |bytes| would be a valid T.61 string.
// Clearly, a sequence of bytes comprised solely of valid T.61
// codepoints does not imply that the encoding MUST be T.61, rather that
// you would not encounter an error trying to interpret the data as such.
func couldBeT61(bytes []byte) bool {
for _, b := range bytes {
switch b {
case 0x00:
// Since we're guessing at (incorrect) encodings for a
// PrintableString, we'll err on the side of caution and disallow
// strings with a NUL in them, don't want to re-create a PayPal NUL
// situation in monitors.
fallthrough
case 0x23, 0x24, 0x5C, 0x5E, 0x60, 0x7B, 0x7D, 0x7E, 0xA5, 0xA6, 0xAC, 0xAD, 0xAE, 0xAF,
0xB9, 0xBA, 0xC0, 0xC9, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9,
0xDA, 0xDB, 0xDC, 0xDE, 0xDF, 0xE5, 0xFF:
// These are all invalid code points in T.61, so it can't be a T.61 string.
return false
}
}
return true
}
// Converts the data in |bytes| to the equivalent UTF-8 string.
func iso8859_1ToUTF8(bytes []byte) string {
buf := make([]rune, len(bytes))
for i, b := range bytes {
buf[i] = rune(b)
}
return string(buf)
}
// END CT CHANGES
// parseField is the main parsing function. Given a byte slice and an offset
// into the array, it will try to parse a suitable ASN.1 value out and store it
// in the given Value.
func parseField(v reflect.Value, bytes []byte, initOffset int, params fieldParameters) (offset int, err error) {
offset = initOffset
fieldType := v.Type()
// If we have run out of data, it may be that there are optional elements at the end.
if offset == len(bytes) {
if !setDefaultValue(v, params) {
err = SyntaxError{"sequence truncated"}
}
return
}
// Deal with raw values.
if fieldType == rawValueType {
var t tagAndLength
t, offset, err = parseTagAndLength(bytes, offset)
if err != nil {
return
}
if invalidLength(offset, t.length, len(bytes)) {
err = SyntaxError{"data truncated"}
return
}
result := RawValue{t.class, t.tag, t.isCompound, bytes[offset : offset+t.length], bytes[initOffset : offset+t.length]}
offset += t.length
v.Set(reflect.ValueOf(result))
return
}
// Deal with the ANY type.
if ifaceType := fieldType; ifaceType.Kind() == reflect.Interface && ifaceType.NumMethod() == 0 {
var t tagAndLength
t, offset, err = parseTagAndLength(bytes, offset)
if err != nil {
return
}
if invalidLength(offset, t.length, len(bytes)) {
err = SyntaxError{"data truncated"}
return
}
var result interface{}
if !t.isCompound && t.class == classUniversal {
innerBytes := bytes[offset : offset+t.length]
switch t.tag {
case tagPrintableString:
result, err = parsePrintableString(innerBytes)
// START CT CHANGES
if err != nil && strings.Contains(err.Error(), "PrintableString contains invalid character") {
// Probably an ISO8859-1 string stuffed in, check if it
// would be valid and assume that's what's happened if so,
// otherwise try T.61, failing that give up and just assign
// the bytes
switch {
case couldBeISO8859_1(innerBytes):
result, err = iso8859_1ToUTF8(innerBytes), nil
case couldBeT61(innerBytes):
result, err = parseT61String(innerBytes)
default:
result = nil
err = errors.New("PrintableString contains invalid character, but couldn't determine correct String type.")
}
}
// END CT CHANGES
case tagIA5String:
result, err = parseIA5String(innerBytes)
case tagT61String:
result, err = parseT61String(innerBytes)
case tagUTF8String:
result, err = parseUTF8String(innerBytes)
case tagInteger:
result, err = parseInt64(innerBytes)
case tagBitString:
result, err = parseBitString(innerBytes)
case tagOID:
result, err = parseObjectIdentifier(innerBytes)
case tagUTCTime:
result, err = parseUTCTime(innerBytes)
case tagOctetString:
result = innerBytes
default:
// If we don't know how to handle the type, we just leave Value as nil.
}
}
offset += t.length
if err != nil {
return
}
if result != nil {
v.Set(reflect.ValueOf(result))
}
return
}
universalTag, compoundType, ok1 := getUniversalType(fieldType)
if !ok1 {
err = StructuralError{fmt.Sprintf("unknown Go type: %v", fieldType)}
return
}
t, offset, err := parseTagAndLength(bytes, offset)
if err != nil {
return
}
if params.explicit {
expectedClass := classContextSpecific
if params.application {
expectedClass = classApplication
}
if t.class == expectedClass && t.tag == *params.tag && (t.length == 0 || t.isCompound) {
if t.length > 0 {
t, offset, err = parseTagAndLength(bytes, offset)
if err != nil {
return
}
} else {
if fieldType != flagType {
err = StructuralError{"zero length explicit tag was not an asn1.Flag"}
return
}
v.SetBool(true)
return
}
} else {
// The tags didn't match, it might be an optional element.
ok := setDefaultValue(v, params)
if ok {
offset = initOffset
} else {
err = StructuralError{"explicitly tagged member didn't match"}
}
return
}
}
// Special case for strings: all the ASN.1 string types map to the Go
// type string. getUniversalType returns the tag for PrintableString
// when it sees a string, so if we see a different string type on the
// wire, we change the universal type to match.
if universalTag == tagPrintableString {
switch t.tag {
case tagIA5String, tagGeneralString, tagT61String, tagUTF8String:
universalTag = t.tag
}
}
// Special case for time: UTCTime and GeneralizedTime both map to the
// Go type time.Time.
if universalTag == tagUTCTime && t.tag == tagGeneralizedTime {
universalTag = tagGeneralizedTime
}
expectedClass := classUniversal
expectedTag := universalTag
if !params.explicit && params.tag != nil {
expectedClass = classContextSpecific
expectedTag = *params.tag
}
if !params.explicit && params.application && params.tag != nil {
expectedClass = classApplication
expectedTag = *params.tag
}
// We have unwrapped any explicit tagging at this point.
if t.class != expectedClass || t.tag != expectedTag || t.isCompound != compoundType {
// Tags don't match. Again, it could be an optional element.
ok := setDefaultValue(v, params)
if ok {
offset = initOffset
} else {
err = StructuralError{fmt.Sprintf("tags don't match (%d vs %+v) %+v %s @%d", expectedTag, t, params, fieldType.Name(), offset)}
}
return
}
if invalidLength(offset, t.length, len(bytes)) {
err = SyntaxError{"data truncated"}
return
}
innerBytes := bytes[offset : offset+t.length]
offset += t.length
// We deal with the structures defined in this package first.
switch fieldType {
case objectIdentifierType:
newSlice, err1 := parseObjectIdentifier(innerBytes)
v.Set(reflect.MakeSlice(v.Type(), len(newSlice), len(newSlice)))
if err1 == nil {
reflect.Copy(v, reflect.ValueOf(newSlice))
}
err = err1
return
case bitStringType:
bs, err1 := parseBitString(innerBytes)
if err1 == nil {
v.Set(reflect.ValueOf(bs))
}
err = err1
return
case timeType:
var time time.Time
var err1 error
if universalTag == tagUTCTime {
time, err1 = parseUTCTime(innerBytes)
} else {
time, err1 = parseGeneralizedTime(innerBytes)
}
if err1 == nil {
v.Set(reflect.ValueOf(time))
}
err = err1
return
case enumeratedType:
parsedInt, err1 := parseInt32(innerBytes)
if err1 == nil {
v.SetInt(int64(parsedInt))
}
err = err1
return
case flagType:
v.SetBool(true)
return
case bigIntType:
parsedInt := parseBigInt(innerBytes)
v.Set(reflect.ValueOf(parsedInt))
return
}
switch val := v; val.Kind() {
case reflect.Bool:
parsedBool, err1 := parseBool(innerBytes)
if err1 == nil {
val.SetBool(parsedBool)
}
err = err1
return
case reflect.Int, reflect.Int32, reflect.Int64:
if val.Type().Size() == 4 {
parsedInt, err1 := parseInt32(innerBytes)
if err1 == nil {
val.SetInt(int64(parsedInt))
}
err = err1
} else {
parsedInt, err1 := parseInt64(innerBytes)
if err1 == nil {
val.SetInt(parsedInt)
}
err = err1
}
return
// TODO(dfc) Add support for the remaining integer types
case reflect.Struct:
structType := fieldType
if structType.NumField() > 0 &&
structType.Field(0).Type == rawContentsType {
bytes := bytes[initOffset:offset]
val.Field(0).Set(reflect.ValueOf(RawContent(bytes)))
}
innerOffset := 0
for i := 0; i < structType.NumField(); i++ {
field := structType.Field(i)
if i == 0 && field.Type == rawContentsType {
continue
}
innerOffset, err = parseField(val.Field(i), innerBytes, innerOffset, parseFieldParameters(field.Tag.Get("asn1")))
if err != nil {
return
}
}
// We allow extra bytes at the end of the SEQUENCE because
// adding elements to the end has been used in X.509 as the
// version numbers have increased.
return
case reflect.Slice:
sliceType := fieldType
if sliceType.Elem().Kind() == reflect.Uint8 {
val.Set(reflect.MakeSlice(sliceType, len(innerBytes), len(innerBytes)))
reflect.Copy(val, reflect.ValueOf(innerBytes))
return
}
newSlice, err1 := parseSequenceOf(innerBytes, sliceType, sliceType.Elem())
if err1 == nil {
val.Set(newSlice)
}
err = err1
return
case reflect.String:
var v string
switch universalTag {
case tagPrintableString:
v, err = parsePrintableString(innerBytes)
case tagIA5String:
v, err = parseIA5String(innerBytes)
case tagT61String:
v, err = parseT61String(innerBytes)
case tagUTF8String:
v, err = parseUTF8String(innerBytes)
case tagGeneralString:
// GeneralString is specified in ISO-2022/ECMA-35,
// A brief review suggests that it includes structures
// that allow the encoding to change midstring and
// such. We give up and pass it as an 8-bit string.
v, err = parseT61String(innerBytes)
default:
err = SyntaxError{fmt.Sprintf("internal error: unknown string type %d", universalTag)}
}
if err == nil {
val.SetString(v)
}
return
}
err = StructuralError{"unsupported: " + v.Type().String()}
return
}
// setDefaultValue is used to install a default value, from a tag string, into
// a Value. It is successful is the field was optional, even if a default value
// wasn't provided or it failed to install it into the Value.
func setDefaultValue(v reflect.Value, params fieldParameters) (ok bool) {
if !params.optional {
return
}
ok = true
if params.defaultValue == nil {
return
}
switch val := v; val.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
val.SetInt(*params.defaultValue)
}
return
}
// Unmarshal parses the DER-encoded ASN.1 data structure b
// and uses the reflect package to fill in an arbitrary value pointed at by val.
// Because Unmarshal uses the reflect package, the structs
// being written to must use upper case field names.
//
// An ASN.1 INTEGER can be written to an int, int32, int64,
// or *big.Int (from the math/big package).
// If the encoded value does not fit in the Go type,
// Unmarshal returns a parse error.
//
// An ASN.1 BIT STRING can be written to a BitString.
//
// An ASN.1 OCTET STRING can be written to a []byte.
//
// An ASN.1 OBJECT IDENTIFIER can be written to an
// ObjectIdentifier.
//
// An ASN.1 ENUMERATED can be written to an Enumerated.
//
// An ASN.1 UTCTIME or GENERALIZEDTIME can be written to a time.Time.
//
// An ASN.1 PrintableString or IA5String can be written to a string.
//
// Any of the above ASN.1 values can be written to an interface{}.
// The value stored in the interface has the corresponding Go type.
// For integers, that type is int64.
//
// An ASN.1 SEQUENCE OF x or SET OF x can be written
// to a slice if an x can be written to the slice's element type.
//
// An ASN.1 SEQUENCE or SET can be written to a struct
// if each of the elements in the sequence can be
// written to the corresponding element in the struct.
//
// The following tags on struct fields have special meaning to Unmarshal:
//
// optional marks the field as ASN.1 OPTIONAL
// [explicit] tag:x specifies the ASN.1 tag number; implies ASN.1 CONTEXT SPECIFIC
// default:x sets the default value for optional integer fields
//
// If the type of the first field of a structure is RawContent then the raw
// ASN1 contents of the struct will be stored in it.
//
// Other ASN.1 types are not supported; if it encounters them,
// Unmarshal returns a parse error.
func Unmarshal(b []byte, val interface{}) (rest []byte, err error) {
return UnmarshalWithParams(b, val, "")
}
// UnmarshalWithParams allows field parameters to be specified for the
// top-level element. The form of the params is the same as the field tags.
func UnmarshalWithParams(b []byte, val interface{}, params string) (rest []byte, err error) {
v := reflect.ValueOf(val).Elem()
offset, err := parseField(v, b, 0, parseFieldParameters(params))
if err != nil {
return nil, err
}
return b[offset:], nil
}

View File

@@ -0,0 +1,163 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package asn1
import (
"reflect"
"strconv"
"strings"
)
// ASN.1 objects have metadata preceding them:
// the tag: the type of the object
// a flag denoting if this object is compound or not
// the class type: the namespace of the tag
// the length of the object, in bytes
// Here are some standard tags and classes
const (
tagBoolean = 1
tagInteger = 2
tagBitString = 3
tagOctetString = 4
tagOID = 6
tagEnum = 10
tagUTF8String = 12
tagSequence = 16
tagSet = 17
tagPrintableString = 19
tagT61String = 20
tagIA5String = 22
tagUTCTime = 23
tagGeneralizedTime = 24
tagGeneralString = 27
)
const (
classUniversal = 0
classApplication = 1
classContextSpecific = 2
classPrivate = 3
)
type tagAndLength struct {
class, tag, length int
isCompound bool
}
// ASN.1 has IMPLICIT and EXPLICIT tags, which can be translated as "instead
// of" and "in addition to". When not specified, every primitive type has a
// default tag in the UNIVERSAL class.
//
// For example: a BIT STRING is tagged [UNIVERSAL 3] by default (although ASN.1
// doesn't actually have a UNIVERSAL keyword). However, by saying [IMPLICIT
// CONTEXT-SPECIFIC 42], that means that the tag is replaced by another.
//
// On the other hand, if it said [EXPLICIT CONTEXT-SPECIFIC 10], then an
// /additional/ tag would wrap the default tag. This explicit tag will have the
// compound flag set.
//
// (This is used in order to remove ambiguity with optional elements.)
//
// You can layer EXPLICIT and IMPLICIT tags to an arbitrary depth, however we
// don't support that here. We support a single layer of EXPLICIT or IMPLICIT
// tagging with tag strings on the fields of a structure.
// fieldParameters is the parsed representation of tag string from a structure field.
type fieldParameters struct {
optional bool // true iff the field is OPTIONAL
explicit bool // true iff an EXPLICIT tag is in use.
application bool // true iff an APPLICATION tag is in use.
defaultValue *int64 // a default value for INTEGER typed fields (maybe nil).
tag *int // the EXPLICIT or IMPLICIT tag (maybe nil).
stringType int // the string tag to use when marshaling.
set bool // true iff this should be encoded as a SET
omitEmpty bool // true iff this should be omitted if empty when marshaling.
// Invariants:
// if explicit is set, tag is non-nil.
}
// Given a tag string with the format specified in the package comment,
// parseFieldParameters will parse it into a fieldParameters structure,
// ignoring unknown parts of the string.
func parseFieldParameters(str string) (ret fieldParameters) {
for _, part := range strings.Split(str, ",") {
switch {
case part == "optional":
ret.optional = true
case part == "explicit":
ret.explicit = true
if ret.tag == nil {
ret.tag = new(int)
}
case part == "ia5":
ret.stringType = tagIA5String
case part == "printable":
ret.stringType = tagPrintableString
case part == "utf8":
ret.stringType = tagUTF8String
case strings.HasPrefix(part, "default:"):
i, err := strconv.ParseInt(part[8:], 10, 64)
if err == nil {
ret.defaultValue = new(int64)
*ret.defaultValue = i
}
case strings.HasPrefix(part, "tag:"):
i, err := strconv.Atoi(part[4:])
if err == nil {
ret.tag = new(int)
*ret.tag = i
}
case part == "set":
ret.set = true
case part == "application":
ret.application = true
if ret.tag == nil {
ret.tag = new(int)
}
case part == "omitempty":
ret.omitEmpty = true
}
}
return
}
// Given a reflected Go type, getUniversalType returns the default tag number
// and expected compound flag.
func getUniversalType(t reflect.Type) (tagNumber int, isCompound, ok bool) {
switch t {
case objectIdentifierType:
return tagOID, false, true
case bitStringType:
return tagBitString, false, true
case timeType:
return tagUTCTime, false, true
case enumeratedType:
return tagEnum, false, true
case bigIntType:
return tagInteger, false, true
}
switch t.Kind() {
case reflect.Bool:
return tagBoolean, false, true
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return tagInteger, false, true
case reflect.Struct:
return tagSequence, true, true
case reflect.Slice:
if t.Elem().Kind() == reflect.Uint8 {
return tagOctetString, false, true
}
if strings.HasSuffix(t.Name(), "SET") {
return tagSet, true, true
}
return tagSequence, true, true
case reflect.String:
return tagPrintableString, false, true
}
return 0, false, false
}

View File

@@ -0,0 +1,581 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package asn1
import (
"bytes"
"errors"
"fmt"
"io"
"math/big"
"reflect"
"time"
"unicode/utf8"
)
// A forkableWriter is an in-memory buffer that can be
// 'forked' to create new forkableWriters that bracket the
// original. After
// pre, post := w.fork();
// the overall sequence of bytes represented is logically w+pre+post.
type forkableWriter struct {
*bytes.Buffer
pre, post *forkableWriter
}
func newForkableWriter() *forkableWriter {
return &forkableWriter{new(bytes.Buffer), nil, nil}
}
func (f *forkableWriter) fork() (pre, post *forkableWriter) {
if f.pre != nil || f.post != nil {
panic("have already forked")
}
f.pre = newForkableWriter()
f.post = newForkableWriter()
return f.pre, f.post
}
func (f *forkableWriter) Len() (l int) {
l += f.Buffer.Len()
if f.pre != nil {
l += f.pre.Len()
}
if f.post != nil {
l += f.post.Len()
}
return
}
func (f *forkableWriter) writeTo(out io.Writer) (n int, err error) {
n, err = out.Write(f.Bytes())
if err != nil {
return
}
var nn int
if f.pre != nil {
nn, err = f.pre.writeTo(out)
n += nn
if err != nil {
return
}
}
if f.post != nil {
nn, err = f.post.writeTo(out)
n += nn
}
return
}
func marshalBase128Int(out *forkableWriter, n int64) (err error) {
if n == 0 {
err = out.WriteByte(0)
return
}
l := 0
for i := n; i > 0; i >>= 7 {
l++
}
for i := l - 1; i >= 0; i-- {
o := byte(n >> uint(i*7))
o &= 0x7f
if i != 0 {
o |= 0x80
}
err = out.WriteByte(o)
if err != nil {
return
}
}
return nil
}
func marshalInt64(out *forkableWriter, i int64) (err error) {
n := int64Length(i)
for ; n > 0; n-- {
err = out.WriteByte(byte(i >> uint((n-1)*8)))
if err != nil {
return
}
}
return nil
}
func int64Length(i int64) (numBytes int) {
numBytes = 1
for i > 127 {
numBytes++
i >>= 8
}
for i < -128 {
numBytes++
i >>= 8
}
return
}
func marshalBigInt(out *forkableWriter, n *big.Int) (err error) {
if n.Sign() < 0 {
// A negative number has to be converted to two's-complement
// form. So we'll subtract 1 and invert. If the
// most-significant-bit isn't set then we'll need to pad the
// beginning with 0xff in order to keep the number negative.
nMinus1 := new(big.Int).Neg(n)
nMinus1.Sub(nMinus1, bigOne)
bytes := nMinus1.Bytes()
for i := range bytes {
bytes[i] ^= 0xff
}
if len(bytes) == 0 || bytes[0]&0x80 == 0 {
err = out.WriteByte(0xff)
if err != nil {
return
}
}
_, err = out.Write(bytes)
} else if n.Sign() == 0 {
// Zero is written as a single 0 zero rather than no bytes.
err = out.WriteByte(0x00)
} else {
bytes := n.Bytes()
if len(bytes) > 0 && bytes[0]&0x80 != 0 {
// We'll have to pad this with 0x00 in order to stop it
// looking like a negative number.
err = out.WriteByte(0)
if err != nil {
return
}
}
_, err = out.Write(bytes)
}
return
}
func marshalLength(out *forkableWriter, i int) (err error) {
n := lengthLength(i)
for ; n > 0; n-- {
err = out.WriteByte(byte(i >> uint((n-1)*8)))
if err != nil {
return
}
}
return nil
}
func lengthLength(i int) (numBytes int) {
numBytes = 1
for i > 255 {
numBytes++
i >>= 8
}
return
}
func marshalTagAndLength(out *forkableWriter, t tagAndLength) (err error) {
b := uint8(t.class) << 6
if t.isCompound {
b |= 0x20
}
if t.tag >= 31 {
b |= 0x1f
err = out.WriteByte(b)
if err != nil {
return
}
err = marshalBase128Int(out, int64(t.tag))
if err != nil {
return
}
} else {
b |= uint8(t.tag)
err = out.WriteByte(b)
if err != nil {
return
}
}
if t.length >= 128 {
l := lengthLength(t.length)
err = out.WriteByte(0x80 | byte(l))
if err != nil {
return
}
err = marshalLength(out, t.length)
if err != nil {
return
}
} else {
err = out.WriteByte(byte(t.length))
if err != nil {
return
}
}
return nil
}
func marshalBitString(out *forkableWriter, b BitString) (err error) {
paddingBits := byte((8 - b.BitLength%8) % 8)
err = out.WriteByte(paddingBits)
if err != nil {
return
}
_, err = out.Write(b.Bytes)
return
}
func marshalObjectIdentifier(out *forkableWriter, oid []int) (err error) {
if len(oid) < 2 || oid[0] > 2 || (oid[0] < 2 && oid[1] >= 40) {
return StructuralError{"invalid object identifier"}
}
err = marshalBase128Int(out, int64(oid[0]*40+oid[1]))
if err != nil {
return
}
for i := 2; i < len(oid); i++ {
err = marshalBase128Int(out, int64(oid[i]))
if err != nil {
return
}
}
return
}
func marshalPrintableString(out *forkableWriter, s string) (err error) {
b := []byte(s)
for _, c := range b {
if !isPrintable(c) {
return StructuralError{"PrintableString contains invalid character"}
}
}
_, err = out.Write(b)
return
}
func marshalIA5String(out *forkableWriter, s string) (err error) {
b := []byte(s)
for _, c := range b {
if c > 127 {
return StructuralError{"IA5String contains invalid character"}
}
}
_, err = out.Write(b)
return
}
func marshalUTF8String(out *forkableWriter, s string) (err error) {
_, err = out.Write([]byte(s))
return
}
func marshalTwoDigits(out *forkableWriter, v int) (err error) {
err = out.WriteByte(byte('0' + (v/10)%10))
if err != nil {
return
}
return out.WriteByte(byte('0' + v%10))
}
func marshalUTCTime(out *forkableWriter, t time.Time) (err error) {
year, month, day := t.Date()
switch {
case 1950 <= year && year < 2000:
err = marshalTwoDigits(out, int(year-1900))
case 2000 <= year && year < 2050:
err = marshalTwoDigits(out, int(year-2000))
default:
return StructuralError{"cannot represent time as UTCTime"}
}
if err != nil {
return
}
err = marshalTwoDigits(out, int(month))
if err != nil {
return
}
err = marshalTwoDigits(out, day)
if err != nil {
return
}
hour, min, sec := t.Clock()
err = marshalTwoDigits(out, hour)
if err != nil {
return
}
err = marshalTwoDigits(out, min)
if err != nil {
return
}
err = marshalTwoDigits(out, sec)
if err != nil {
return
}
_, offset := t.Zone()
switch {
case offset/60 == 0:
err = out.WriteByte('Z')
return
case offset > 0:
err = out.WriteByte('+')
case offset < 0:
err = out.WriteByte('-')
}
if err != nil {
return
}
offsetMinutes := offset / 60
if offsetMinutes < 0 {
offsetMinutes = -offsetMinutes
}
err = marshalTwoDigits(out, offsetMinutes/60)
if err != nil {
return
}
err = marshalTwoDigits(out, offsetMinutes%60)
return
}
func stripTagAndLength(in []byte) []byte {
_, offset, err := parseTagAndLength(in, 0)
if err != nil {
return in
}
return in[offset:]
}
func marshalBody(out *forkableWriter, value reflect.Value, params fieldParameters) (err error) {
switch value.Type() {
case timeType:
return marshalUTCTime(out, value.Interface().(time.Time))
case bitStringType:
return marshalBitString(out, value.Interface().(BitString))
case objectIdentifierType:
return marshalObjectIdentifier(out, value.Interface().(ObjectIdentifier))
case bigIntType:
return marshalBigInt(out, value.Interface().(*big.Int))
}
switch v := value; v.Kind() {
case reflect.Bool:
if v.Bool() {
return out.WriteByte(255)
} else {
return out.WriteByte(0)
}
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return marshalInt64(out, int64(v.Int()))
case reflect.Struct:
t := v.Type()
startingField := 0
// If the first element of the structure is a non-empty
// RawContents, then we don't bother serializing the rest.
if t.NumField() > 0 && t.Field(0).Type == rawContentsType {
s := v.Field(0)
if s.Len() > 0 {
bytes := make([]byte, s.Len())
for i := 0; i < s.Len(); i++ {
bytes[i] = uint8(s.Index(i).Uint())
}
/* The RawContents will contain the tag and
* length fields but we'll also be writing
* those ourselves, so we strip them out of
* bytes */
_, err = out.Write(stripTagAndLength(bytes))
return
} else {
startingField = 1
}
}
for i := startingField; i < t.NumField(); i++ {
var pre *forkableWriter
pre, out = out.fork()
err = marshalField(pre, v.Field(i), parseFieldParameters(t.Field(i).Tag.Get("asn1")))
if err != nil {
return
}
}
return
case reflect.Slice:
sliceType := v.Type()
if sliceType.Elem().Kind() == reflect.Uint8 {
bytes := make([]byte, v.Len())
for i := 0; i < v.Len(); i++ {
bytes[i] = uint8(v.Index(i).Uint())
}
_, err = out.Write(bytes)
return
}
var fp fieldParameters
for i := 0; i < v.Len(); i++ {
var pre *forkableWriter
pre, out = out.fork()
err = marshalField(pre, v.Index(i), fp)
if err != nil {
return
}
}
return
case reflect.String:
switch params.stringType {
case tagIA5String:
return marshalIA5String(out, v.String())
case tagPrintableString:
return marshalPrintableString(out, v.String())
default:
return marshalUTF8String(out, v.String())
}
}
return StructuralError{"unknown Go type"}
}
func marshalField(out *forkableWriter, v reflect.Value, params fieldParameters) (err error) {
// If the field is an interface{} then recurse into it.
if v.Kind() == reflect.Interface && v.Type().NumMethod() == 0 {
return marshalField(out, v.Elem(), params)
}
if v.Kind() == reflect.Slice && v.Len() == 0 && params.omitEmpty {
return
}
if params.optional && reflect.DeepEqual(v.Interface(), reflect.Zero(v.Type()).Interface()) {
return
}
if v.Type() == rawValueType {
rv := v.Interface().(RawValue)
if len(rv.FullBytes) != 0 {
_, err = out.Write(rv.FullBytes)
} else {
err = marshalTagAndLength(out, tagAndLength{rv.Class, rv.Tag, len(rv.Bytes), rv.IsCompound})
if err != nil {
return
}
_, err = out.Write(rv.Bytes)
}
return
}
tag, isCompound, ok := getUniversalType(v.Type())
if !ok {
err = StructuralError{fmt.Sprintf("unknown Go type: %v", v.Type())}
return
}
class := classUniversal
if params.stringType != 0 && tag != tagPrintableString {
return StructuralError{"explicit string type given to non-string member"}
}
if tag == tagPrintableString {
if params.stringType == 0 {
// This is a string without an explicit string type. We'll use
// a PrintableString if the character set in the string is
// sufficiently limited, otherwise we'll use a UTF8String.
for _, r := range v.String() {
if r >= utf8.RuneSelf || !isPrintable(byte(r)) {
if !utf8.ValidString(v.String()) {
return errors.New("asn1: string not valid UTF-8")
}
tag = tagUTF8String
break
}
}
} else {
tag = params.stringType
}
}
if params.set {
if tag != tagSequence {
return StructuralError{"non sequence tagged as set"}
}
tag = tagSet
}
tags, body := out.fork()
err = marshalBody(body, v, params)
if err != nil {
return
}
bodyLen := body.Len()
var explicitTag *forkableWriter
if params.explicit {
explicitTag, tags = tags.fork()
}
if !params.explicit && params.tag != nil {
// implicit tag.
tag = *params.tag
class = classContextSpecific
}
err = marshalTagAndLength(tags, tagAndLength{class, tag, bodyLen, isCompound})
if err != nil {
return
}
if params.explicit {
err = marshalTagAndLength(explicitTag, tagAndLength{
class: classContextSpecific,
tag: *params.tag,
length: bodyLen + tags.Len(),
isCompound: true,
})
}
return nil
}
// Marshal returns the ASN.1 encoding of val.
func Marshal(val interface{}) ([]byte, error) {
var out bytes.Buffer
v := reflect.ValueOf(val)
f := newForkableWriter()
err := marshalField(f, v, fieldParameters{})
if err != nil {
return nil, err
}
_, err = f.writeTo(&out)
return out.Bytes(), nil
}

View File

@@ -0,0 +1,358 @@
// Package client is a CT log client implementation and contains types and code
// for interacting with RFC6962-compliant CT Log instances.
// See http://tools.ietf.org/html/rfc6962 for details
package client
import (
"bytes"
"crypto/sha256"
"encoding/base64"
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"log"
"net/http"
"strconv"
"time"
"github.com/google/certificate-transparency/go"
"github.com/mreiferson/go-httpclient"
"golang.org/x/net/context"
)
// URI paths for CT Log endpoints
const (
AddChainPath = "/ct/v1/add-chain"
AddPreChainPath = "/ct/v1/add-pre-chain"
GetSTHPath = "/ct/v1/get-sth"
GetEntriesPath = "/ct/v1/get-entries"
)
// LogClient represents a client for a given CT Log instance
type LogClient struct {
uri string // the base URI of the log. e.g. http://ct.googleapis/pilot
httpClient *http.Client // used to interact with the log via HTTP
}
//////////////////////////////////////////////////////////////////////////////////
// JSON structures follow.
// These represent the structures returned by the CT Log server.
//////////////////////////////////////////////////////////////////////////////////
// addChainRequest represents the JSON request body sent to the add-chain CT
// method.
type addChainRequest struct {
Chain []string `json:"chain"`
}
// addChainResponse represents the JSON response to the add-chain CT method.
// An SCT represents a Log's promise to integrate a [pre-]certificate into the
// log within a defined period of time.
type addChainResponse struct {
SCTVersion ct.Version `json:"sct_version"` // SCT structure version
ID string `json:"id"` // Log ID
Timestamp uint64 `json:"timestamp"` // Timestamp of issuance
Extensions string `json:"extensions"` // Holder for any CT extensions
Signature string `json:"signature"` // Log signature for this SCT
}
// getSTHResponse respresents the JSON response to the get-sth CT method
type getSTHResponse struct {
TreeSize uint64 `json:"tree_size"` // Number of certs in the current tree
Timestamp uint64 `json:"timestamp"` // Time that the tree was created
SHA256RootHash string `json:"sha256_root_hash"` // Root hash of the tree
TreeHeadSignature string `json:"tree_head_signature"` // Log signature for this STH
}
// base64LeafEntry respresents a Base64 encoded leaf entry
type base64LeafEntry struct {
LeafInput string `json:"leaf_input"`
ExtraData string `json:"extra_data"`
}
// getEntriesReponse respresents the JSON response to the CT get-entries method
type getEntriesResponse struct {
Entries []base64LeafEntry `json:"entries"` // the list of returned entries
}
// getConsistencyProofResponse represents the JSON response to the CT get-consistency-proof method
type getConsistencyProofResponse struct {
Consistency []string `json:"consistency"`
}
// getAuditProofResponse represents the JSON response to the CT get-audit-proof method
type getAuditProofResponse struct {
Hash []string `json:"hash"` // the hashes which make up the proof
TreeSize uint64 `json:"tree_size"` // the tree size against which this proof is constructed
}
// getAcceptedRootsResponse represents the JSON response to the CT get-roots method.
type getAcceptedRootsResponse struct {
Certificates []string `json:"certificates"`
}
// getEntryAndProodReponse represents the JSON response to the CT get-entry-and-proof method
type getEntryAndProofResponse struct {
LeafInput string `json:"leaf_input"` // the entry itself
ExtraData string `json:"extra_data"` // any chain provided when the entry was added to the log
AuditPath []string `json:"audit_path"` // the corresponding proof
}
// New constructs a new LogClient instance.
// |uri| is the base URI of the CT log instance to interact with, e.g.
// http://ct.googleapis.com/pilot
func New(uri string) *LogClient {
var c LogClient
c.uri = uri
transport := &httpclient.Transport{
ConnectTimeout: 10 * time.Second,
RequestTimeout: 30 * time.Second,
ResponseHeaderTimeout: 30 * time.Second,
MaxIdleConnsPerHost: 10,
DisableKeepAlives: false,
}
c.httpClient = &http.Client{Transport: transport}
return &c
}
// Makes a HTTP call to |uri|, and attempts to parse the response as a JSON
// representation of the structure in |res|.
// Returns a non-nil |error| if there was a problem.
func (c *LogClient) fetchAndParse(uri string, res interface{}) error {
req, err := http.NewRequest("GET", uri, nil)
if err != nil {
return err
}
req.Header.Set("Keep-Alive", "timeout=15, max=100")
resp, err := c.httpClient.Do(req)
var body []byte
if resp != nil {
body, err = ioutil.ReadAll(resp.Body)
resp.Body.Close()
if err != nil {
return err
}
}
if err != nil {
return err
}
if err = json.Unmarshal(body, &res); err != nil {
return err
}
return nil
}
// Makes a HTTP POST call to |uri|, and attempts to parse the response as a JSON
// representation of the structure in |res|.
// Returns a non-nil |error| if there was a problem.
func (c *LogClient) postAndParse(uri string, req interface{}, res interface{}) (*http.Response, string, error) {
postBody, err := json.Marshal(req)
if err != nil {
return nil, "", err
}
httpReq, err := http.NewRequest("POST", uri, bytes.NewReader(postBody))
if err != nil {
return nil, "", err
}
httpReq.Header.Set("Keep-Alive", "timeout=15, max=100")
httpReq.Header.Set("Content-Type", "application/json")
resp, err := c.httpClient.Do(httpReq)
// Read all of the body, if there is one, so that the http.Client can do
// Keep-Alive:
var body []byte
if resp != nil {
body, err = ioutil.ReadAll(resp.Body)
resp.Body.Close()
}
if err != nil {
return resp, string(body), err
}
if resp.StatusCode == 200 {
if err != nil {
return resp, string(body), err
}
if err = json.Unmarshal(body, &res); err != nil {
return resp, string(body), err
}
}
return resp, string(body), nil
}
func backoffForRetry(ctx context.Context, d time.Duration) error {
backoffTimer := time.NewTimer(d)
if ctx != nil {
select {
case <-ctx.Done():
return ctx.Err()
case <-backoffTimer.C:
}
} else {
<-backoffTimer.C
}
return nil
}
// Attempts to add |chain| to the log, using the api end-point specified by
// |path|. If provided context expires before submission is complete an
// error will be returned.
func (c *LogClient) addChainWithRetry(ctx context.Context, path string, chain []ct.ASN1Cert) (*ct.SignedCertificateTimestamp, error) {
var resp addChainResponse
var req addChainRequest
for _, link := range chain {
req.Chain = append(req.Chain, base64.StdEncoding.EncodeToString(link))
}
httpStatus := "Unknown"
backoffSeconds := 0
done := false
for !done {
if backoffSeconds > 0 {
log.Printf("Got %s, backing-off %d seconds", httpStatus, backoffSeconds)
}
err := backoffForRetry(ctx, time.Second*time.Duration(backoffSeconds))
if err != nil {
return nil, err
}
if backoffSeconds > 0 {
backoffSeconds = 0
}
httpResp, errorBody, err := c.postAndParse(c.uri+path, &req, &resp)
if err != nil {
backoffSeconds = 10
continue
}
switch {
case httpResp.StatusCode == 200:
done = true
case httpResp.StatusCode == 408:
// request timeout, retry immediately
case httpResp.StatusCode == 503:
// Retry
backoffSeconds = 10
if retryAfter := httpResp.Header.Get("Retry-After"); retryAfter != "" {
if seconds, err := strconv.Atoi(retryAfter); err == nil {
backoffSeconds = seconds
}
}
default:
return nil, fmt.Errorf("got HTTP Status %s: %s", httpResp.Status, errorBody)
}
httpStatus = httpResp.Status
}
rawLogID, err := base64.StdEncoding.DecodeString(resp.ID)
if err != nil {
return nil, err
}
rawSignature, err := base64.StdEncoding.DecodeString(resp.Signature)
if err != nil {
return nil, err
}
ds, err := ct.UnmarshalDigitallySigned(bytes.NewReader(rawSignature))
if err != nil {
return nil, err
}
var logID ct.SHA256Hash
copy(logID[:], rawLogID)
return &ct.SignedCertificateTimestamp{
SCTVersion: resp.SCTVersion,
LogID: logID,
Timestamp: resp.Timestamp,
Extensions: ct.CTExtensions(resp.Extensions),
Signature: *ds}, nil
}
// AddChain adds the (DER represented) X509 |chain| to the log.
func (c *LogClient) AddChain(chain []ct.ASN1Cert) (*ct.SignedCertificateTimestamp, error) {
return c.addChainWithRetry(nil, AddChainPath, chain)
}
// AddPreChain adds the (DER represented) Precertificate |chain| to the log.
func (c *LogClient) AddPreChain(chain []ct.ASN1Cert) (*ct.SignedCertificateTimestamp, error) {
return c.addChainWithRetry(nil, AddPreChainPath, chain)
}
// AddChainWithContext adds the (DER represented) X509 |chain| to the log and
// fails if the provided context expires before the chain is submitted.
func (c *LogClient) AddChainWithContext(ctx context.Context, chain []ct.ASN1Cert) (*ct.SignedCertificateTimestamp, error) {
return c.addChainWithRetry(ctx, AddChainPath, chain)
}
// GetSTH retrieves the current STH from the log.
// Returns a populated SignedTreeHead, or a non-nil error.
func (c *LogClient) GetSTH() (sth *ct.SignedTreeHead, err error) {
var resp getSTHResponse
if err = c.fetchAndParse(c.uri+GetSTHPath, &resp); err != nil {
return
}
sth = &ct.SignedTreeHead{
TreeSize: resp.TreeSize,
Timestamp: resp.Timestamp,
}
rawRootHash, err := base64.StdEncoding.DecodeString(resp.SHA256RootHash)
if err != nil {
return nil, fmt.Errorf("invalid base64 encoding in sha256_root_hash: %v", err)
}
if len(rawRootHash) != sha256.Size {
return nil, fmt.Errorf("sha256_root_hash is invalid length, expected %d got %d", sha256.Size, len(rawRootHash))
}
copy(sth.SHA256RootHash[:], rawRootHash)
rawSignature, err := base64.StdEncoding.DecodeString(resp.TreeHeadSignature)
if err != nil {
return nil, errors.New("invalid base64 encoding in tree_head_signature")
}
ds, err := ct.UnmarshalDigitallySigned(bytes.NewReader(rawSignature))
if err != nil {
return nil, err
}
// TODO(alcutter): Verify signature
sth.TreeHeadSignature = *ds
return
}
// GetEntries attempts to retrieve the entries in the sequence [|start|, |end|] from the CT
// log server. (see section 4.6.)
// Returns a slice of LeafInputs or a non-nil error.
func (c *LogClient) GetEntries(start, end int64) ([]ct.LogEntry, error) {
if end < 0 {
return nil, errors.New("end should be >= 0")
}
if end < start {
return nil, errors.New("start should be <= end")
}
var resp getEntriesResponse
err := c.fetchAndParse(fmt.Sprintf("%s%s?start=%d&end=%d", c.uri, GetEntriesPath, start, end), &resp)
if err != nil {
return nil, err
}
entries := make([]ct.LogEntry, len(resp.Entries))
for index, entry := range resp.Entries {
leafBytes, err := base64.StdEncoding.DecodeString(entry.LeafInput)
leaf, err := ct.ReadMerkleTreeLeaf(bytes.NewBuffer(leafBytes))
if err != nil {
return nil, err
}
entries[index].Leaf = *leaf
chainBytes, err := base64.StdEncoding.DecodeString(entry.ExtraData)
var chain []ct.ASN1Cert
switch leaf.TimestampedEntry.EntryType {
case ct.X509LogEntryType:
chain, err = ct.UnmarshalX509ChainArray(chainBytes)
case ct.PrecertLogEntryType:
chain, err = ct.UnmarshalPrecertChainArray(chainBytes)
default:
return nil, fmt.Errorf("saw unknown entry type: %v", leaf.TimestampedEntry.EntryType)
}
if err != nil {
return nil, err
}
entries[index].Chain = chain
entries[index].Index = start + int64(index)
}
return entries, nil
}

View File

@@ -0,0 +1,512 @@
package ct
import (
"bytes"
"container/list"
"crypto"
"encoding/binary"
"errors"
"fmt"
"io"
)
// Variable size structure prefix-header byte lengths
const (
CertificateLengthBytes = 3
PreCertificateLengthBytes = 3
ExtensionsLengthBytes = 2
CertificateChainLengthBytes = 3
SignatureLengthBytes = 2
)
// Max lengths
const (
MaxCertificateLength = (1 << 24) - 1
MaxExtensionsLength = (1 << 16) - 1
)
func writeUint(w io.Writer, value uint64, numBytes int) error {
buf := make([]uint8, numBytes)
for i := 0; i < numBytes; i++ {
buf[numBytes-i-1] = uint8(value & 0xff)
value >>= 8
}
if value != 0 {
return errors.New("numBytes was insufficiently large to represent value")
}
if _, err := w.Write(buf); err != nil {
return err
}
return nil
}
func writeVarBytes(w io.Writer, value []byte, numLenBytes int) error {
if err := writeUint(w, uint64(len(value)), numLenBytes); err != nil {
return err
}
if _, err := w.Write(value); err != nil {
return err
}
return nil
}
func readUint(r io.Reader, numBytes int) (uint64, error) {
var l uint64
for i := 0; i < numBytes; i++ {
l <<= 8
var t uint8
if err := binary.Read(r, binary.BigEndian, &t); err != nil {
return 0, err
}
l |= uint64(t)
}
return l, nil
}
// Reads a variable length array of bytes from |r|. |numLenBytes| specifies the
// number of (BigEndian) prefix-bytes which contain the length of the actual
// array data bytes that follow.
// Allocates an array to hold the contents and returns a slice view into it if
// the read was successful, or an error otherwise.
func readVarBytes(r io.Reader, numLenBytes int) ([]byte, error) {
switch {
case numLenBytes > 8:
return nil, fmt.Errorf("numLenBytes too large (%d)", numLenBytes)
case numLenBytes == 0:
return nil, errors.New("numLenBytes should be > 0")
}
l, err := readUint(r, numLenBytes)
if err != nil {
return nil, err
}
data := make([]byte, l)
n, err := r.Read(data)
if err != nil {
return nil, err
}
if n != int(l) {
return nil, fmt.Errorf("short read: expected %d but got %d", l, n)
}
return data, nil
}
// Reads a list of ASN1Cert types from |r|
func readASN1CertList(r io.Reader, totalLenBytes int, elementLenBytes int) ([]ASN1Cert, error) {
listBytes, err := readVarBytes(r, totalLenBytes)
if err != nil {
return []ASN1Cert{}, err
}
list := list.New()
listReader := bytes.NewReader(listBytes)
var entry []byte
for err == nil {
entry, err = readVarBytes(listReader, elementLenBytes)
if err != nil {
if err != io.EOF {
return []ASN1Cert{}, err
}
} else {
list.PushBack(entry)
}
}
ret := make([]ASN1Cert, list.Len())
i := 0
for e := list.Front(); e != nil; e = e.Next() {
ret[i] = e.Value.([]byte)
i++
}
return ret, nil
}
// ReadTimestampedEntryInto parses the byte-stream representation of a
// TimestampedEntry from |r| and populates the struct |t| with the data. See
// RFC section 3.4 for details on the format.
// Returns a non-nil error if there was a problem.
func ReadTimestampedEntryInto(r io.Reader, t *TimestampedEntry) error {
var err error
if err = binary.Read(r, binary.BigEndian, &t.Timestamp); err != nil {
return err
}
if err = binary.Read(r, binary.BigEndian, &t.EntryType); err != nil {
return err
}
switch t.EntryType {
case X509LogEntryType:
if t.X509Entry, err = readVarBytes(r, CertificateLengthBytes); err != nil {
return err
}
case PrecertLogEntryType:
if err := binary.Read(r, binary.BigEndian, &t.PrecertEntry.IssuerKeyHash); err != nil {
return err
}
if t.PrecertEntry.TBSCertificate, err = readVarBytes(r, PreCertificateLengthBytes); err != nil {
return err
}
default:
return fmt.Errorf("unknown EntryType: %d", t.EntryType)
}
t.Extensions, err = readVarBytes(r, ExtensionsLengthBytes)
return nil
}
// ReadMerkleTreeLeaf parses the byte-stream representation of a MerkleTreeLeaf
// and returns a pointer to a new MerkleTreeLeaf structure containing the
// parsed data.
// See RFC section 3.4 for details on the format.
// Returns a pointer to a new MerkleTreeLeaf or non-nil error if there was a
// problem
func ReadMerkleTreeLeaf(r io.Reader) (*MerkleTreeLeaf, error) {
var m MerkleTreeLeaf
if err := binary.Read(r, binary.BigEndian, &m.Version); err != nil {
return nil, err
}
if m.Version != V1 {
return nil, fmt.Errorf("unknown Version %d", m.Version)
}
if err := binary.Read(r, binary.BigEndian, &m.LeafType); err != nil {
return nil, err
}
if m.LeafType != TimestampedEntryLeafType {
return nil, fmt.Errorf("unknown LeafType %d", m.LeafType)
}
if err := ReadTimestampedEntryInto(r, &m.TimestampedEntry); err != nil {
return nil, err
}
return &m, nil
}
// UnmarshalX509ChainArray unmarshalls the contents of the "chain:" entry in a
// GetEntries response in the case where the entry refers to an X509 leaf.
func UnmarshalX509ChainArray(b []byte) ([]ASN1Cert, error) {
return readASN1CertList(bytes.NewReader(b), CertificateChainLengthBytes, CertificateLengthBytes)
}
// UnmarshalPrecertChainArray unmarshalls the contents of the "chain:" entry in
// a GetEntries response in the case where the entry refers to a Precertificate
// leaf.
func UnmarshalPrecertChainArray(b []byte) ([]ASN1Cert, error) {
var chain []ASN1Cert
reader := bytes.NewReader(b)
// read the pre-cert entry:
precert, err := readVarBytes(reader, CertificateLengthBytes)
if err != nil {
return chain, err
}
chain = append(chain, precert)
// and then read and return the chain up to the root:
remainingChain, err := readASN1CertList(reader, CertificateChainLengthBytes, CertificateLengthBytes)
if err != nil {
return chain, err
}
chain = append(chain, remainingChain...)
return chain, nil
}
// UnmarshalDigitallySigned reconstructs a DigitallySigned structure from a Reader
func UnmarshalDigitallySigned(r io.Reader) (*DigitallySigned, error) {
var h byte
if err := binary.Read(r, binary.BigEndian, &h); err != nil {
return nil, fmt.Errorf("failed to read HashAlgorithm: %v", err)
}
var s byte
if err := binary.Read(r, binary.BigEndian, &s); err != nil {
return nil, fmt.Errorf("failed to read SignatureAlgorithm: %v", err)
}
sig, err := readVarBytes(r, SignatureLengthBytes)
if err != nil {
return nil, fmt.Errorf("failed to read Signature bytes: %v", err)
}
return &DigitallySigned{
HashAlgorithm: HashAlgorithm(h),
SignatureAlgorithm: SignatureAlgorithm(s),
Signature: sig,
}, nil
}
func marshalDigitallySignedHere(ds DigitallySigned, here []byte) ([]byte, error) {
sigLen := len(ds.Signature)
dsOutLen := 2 + SignatureLengthBytes + sigLen
if here == nil {
here = make([]byte, dsOutLen)
}
if len(here) < dsOutLen {
return nil, ErrNotEnoughBuffer
}
here = here[0:dsOutLen]
here[0] = byte(ds.HashAlgorithm)
here[1] = byte(ds.SignatureAlgorithm)
binary.BigEndian.PutUint16(here[2:4], uint16(sigLen))
copy(here[4:], ds.Signature)
return here, nil
}
// MarshalDigitallySigned marshalls a DigitallySigned structure into a byte array
func MarshalDigitallySigned(ds DigitallySigned) ([]byte, error) {
return marshalDigitallySignedHere(ds, nil)
}
func checkCertificateFormat(cert ASN1Cert) error {
if len(cert) == 0 {
return errors.New("certificate is zero length")
}
if len(cert) > MaxCertificateLength {
return errors.New("certificate too large")
}
return nil
}
func checkExtensionsFormat(ext CTExtensions) error {
if len(ext) > MaxExtensionsLength {
return errors.New("extensions too large")
}
return nil
}
func serializeV1CertSCTSignatureInput(timestamp uint64, cert ASN1Cert, ext CTExtensions) ([]byte, error) {
if err := checkCertificateFormat(cert); err != nil {
return nil, err
}
if err := checkExtensionsFormat(ext); err != nil {
return nil, err
}
var buf bytes.Buffer
if err := binary.Write(&buf, binary.BigEndian, V1); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, CertificateTimestampSignatureType); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, timestamp); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, X509LogEntryType); err != nil {
return nil, err
}
if err := writeVarBytes(&buf, cert, CertificateLengthBytes); err != nil {
return nil, err
}
if err := writeVarBytes(&buf, ext, ExtensionsLengthBytes); err != nil {
return nil, err
}
return buf.Bytes(), nil
}
func serializeV1PrecertSCTSignatureInput(timestamp uint64, issuerKeyHash [issuerKeyHashLength]byte, tbs []byte, ext CTExtensions) ([]byte, error) {
if err := checkCertificateFormat(tbs); err != nil {
return nil, err
}
if err := checkExtensionsFormat(ext); err != nil {
return nil, err
}
var buf bytes.Buffer
if err := binary.Write(&buf, binary.BigEndian, V1); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, CertificateTimestampSignatureType); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, timestamp); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, PrecertLogEntryType); err != nil {
return nil, err
}
if _, err := buf.Write(issuerKeyHash[:]); err != nil {
return nil, err
}
if err := writeVarBytes(&buf, tbs, CertificateLengthBytes); err != nil {
return nil, err
}
if err := writeVarBytes(&buf, ext, ExtensionsLengthBytes); err != nil {
return nil, err
}
return buf.Bytes(), nil
}
func serializeV1SCTSignatureInput(sct SignedCertificateTimestamp, entry LogEntry) ([]byte, error) {
if sct.SCTVersion != V1 {
return nil, fmt.Errorf("unsupported SCT version, expected V1, but got %s", sct.SCTVersion)
}
if entry.Leaf.LeafType != TimestampedEntryLeafType {
return nil, fmt.Errorf("Unsupported leaf type %s", entry.Leaf.LeafType)
}
switch entry.Leaf.TimestampedEntry.EntryType {
case X509LogEntryType:
return serializeV1CertSCTSignatureInput(sct.Timestamp, entry.Leaf.TimestampedEntry.X509Entry, entry.Leaf.TimestampedEntry.Extensions)
case PrecertLogEntryType:
return serializeV1PrecertSCTSignatureInput(sct.Timestamp, entry.Leaf.TimestampedEntry.PrecertEntry.IssuerKeyHash,
entry.Leaf.TimestampedEntry.PrecertEntry.TBSCertificate,
entry.Leaf.TimestampedEntry.Extensions)
default:
return nil, fmt.Errorf("unknown TimestampedEntryLeafType %s", entry.Leaf.TimestampedEntry.EntryType)
}
}
// SerializeSCTSignatureInput serializes the passed in sct and log entry into
// the correct format for signing.
func SerializeSCTSignatureInput(sct SignedCertificateTimestamp, entry LogEntry) ([]byte, error) {
switch sct.SCTVersion {
case V1:
return serializeV1SCTSignatureInput(sct, entry)
default:
return nil, fmt.Errorf("unknown SCT version %d", sct.SCTVersion)
}
}
// SerializedLength will return the space (in bytes)
func (sct SignedCertificateTimestamp) SerializedLength() (int, error) {
switch sct.SCTVersion {
case V1:
extLen := len(sct.Extensions)
sigLen := len(sct.Signature.Signature)
return 1 + 32 + 8 + 2 + extLen + 2 + 2 + sigLen, nil
default:
return 0, ErrInvalidVersion
}
}
func serializeV1SCTHere(sct SignedCertificateTimestamp, here []byte) ([]byte, error) {
if sct.SCTVersion != V1 {
return nil, ErrInvalidVersion
}
sctLen, err := sct.SerializedLength()
if err != nil {
return nil, err
}
if here == nil {
here = make([]byte, sctLen)
}
if len(here) < sctLen {
return nil, ErrNotEnoughBuffer
}
if err := checkExtensionsFormat(sct.Extensions); err != nil {
return nil, err
}
here = here[0:sctLen]
// Write Version
here[0] = byte(sct.SCTVersion)
// Write LogID
copy(here[1:33], sct.LogID[:])
// Write Timestamp
binary.BigEndian.PutUint64(here[33:41], sct.Timestamp)
// Write Extensions
extLen := len(sct.Extensions)
binary.BigEndian.PutUint16(here[41:43], uint16(extLen))
n := 43 + extLen
copy(here[43:n], sct.Extensions)
// Write Signature
_, err = marshalDigitallySignedHere(sct.Signature, here[n:])
if err != nil {
return nil, err
}
return here, nil
}
// SerializeSCTHere serializes the passed in sct into the format specified
// by RFC6962 section 3.2.
// If a bytes slice here is provided then it will attempt to serialize into the
// provided byte slice, ErrNotEnoughBuffer will be returned if the buffer is
// too small.
// If a nil byte slice is provided, a buffer for will be allocated for you
// The returned slice will be sliced to the correct length.
func SerializeSCTHere(sct SignedCertificateTimestamp, here []byte) ([]byte, error) {
switch sct.SCTVersion {
case V1:
return serializeV1SCTHere(sct, here)
default:
return nil, fmt.Errorf("unknown SCT version %d", sct.SCTVersion)
}
}
// SerializeSCT serializes the passed in sct into the format specified
// by RFC6962 section 3.2
// Equivalent to SerializeSCTHere(sct, nil)
func SerializeSCT(sct SignedCertificateTimestamp) ([]byte, error) {
return SerializeSCTHere(sct, nil)
}
func deserializeSCTV1(r io.Reader, sct *SignedCertificateTimestamp) error {
if err := binary.Read(r, binary.BigEndian, &sct.LogID); err != nil {
return err
}
if err := binary.Read(r, binary.BigEndian, &sct.Timestamp); err != nil {
return err
}
ext, err := readVarBytes(r, ExtensionsLengthBytes)
if err != nil {
return err
}
sct.Extensions = ext
ds, err := UnmarshalDigitallySigned(r)
if err != nil {
return err
}
sct.Signature = *ds
return nil
}
func DeserializeSCT(r io.Reader) (*SignedCertificateTimestamp, error) {
var sct SignedCertificateTimestamp
if err := binary.Read(r, binary.BigEndian, &sct.SCTVersion); err != nil {
return nil, err
}
switch sct.SCTVersion {
case V1:
return &sct, deserializeSCTV1(r, &sct)
default:
return nil, fmt.Errorf("unknown SCT version %d", sct.SCTVersion)
}
}
func serializeV1STHSignatureInput(sth SignedTreeHead) ([]byte, error) {
if sth.Version != V1 {
return nil, fmt.Errorf("invalid STH version %d", sth.Version)
}
if sth.TreeSize < 0 {
return nil, fmt.Errorf("invalid tree size %d", sth.TreeSize)
}
if len(sth.SHA256RootHash) != crypto.SHA256.Size() {
return nil, fmt.Errorf("invalid TreeHash length, got %d expected %d", len(sth.SHA256RootHash), crypto.SHA256.Size())
}
var buf bytes.Buffer
if err := binary.Write(&buf, binary.BigEndian, V1); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, TreeHashSignatureType); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, sth.Timestamp); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, sth.TreeSize); err != nil {
return nil, err
}
if err := binary.Write(&buf, binary.BigEndian, sth.SHA256RootHash); err != nil {
return nil, err
}
return buf.Bytes(), nil
}
// SerializeSTHSignatureInput serializes the passed in sth into the correct
// format for signing.
func SerializeSTHSignatureInput(sth SignedTreeHead) ([]byte, error) {
switch sth.Version {
case V1:
return serializeV1STHSignatureInput(sth)
default:
return nil, fmt.Errorf("unsupported STH version %d", sth.Version)
}
}

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package ct
import (
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rsa"
"crypto/sha256"
"crypto/x509"
"encoding/asn1"
"encoding/pem"
"errors"
"flag"
"fmt"
"log"
"math/big"
)
var allowVerificationWithNonCompliantKeys = flag.Bool("allow_verification_with_non_compliant_keys", false,
"Allow a SignatureVerifier to use keys which are technically non-compliant with RFC6962.")
// PublicKeyFromPEM parses a PEM formatted block and returns the public key contained within and any remaining unread bytes, or an error.
func PublicKeyFromPEM(b []byte) (crypto.PublicKey, SHA256Hash, []byte, error) {
p, rest := pem.Decode(b)
if p == nil {
return nil, [sha256.Size]byte{}, rest, fmt.Errorf("no PEM block found in %s", string(b))
}
k, err := x509.ParsePKIXPublicKey(p.Bytes)
return k, sha256.Sum256(p.Bytes), rest, err
}
// SignatureVerifier can verify signatures on SCTs and STHs
type SignatureVerifier struct {
pubKey crypto.PublicKey
}
// NewSignatureVerifier creates a new SignatureVerifier using the passed in PublicKey.
func NewSignatureVerifier(pk crypto.PublicKey) (*SignatureVerifier, error) {
switch pkType := pk.(type) {
case *rsa.PublicKey:
if pkType.N.BitLen() < 2048 {
e := fmt.Errorf("public key is RSA with < 2048 bits (size:%d)", pkType.N.BitLen())
if !(*allowVerificationWithNonCompliantKeys) {
return nil, e
}
log.Printf("WARNING: %v", e)
}
case *ecdsa.PublicKey:
params := *(pkType.Params())
if params != *elliptic.P256().Params() {
e := fmt.Errorf("public is ECDSA, but not on the P256 curve")
if !(*allowVerificationWithNonCompliantKeys) {
return nil, e
}
log.Printf("WARNING: %v", e)
}
default:
return nil, fmt.Errorf("Unsupported public key type %v", pkType)
}
return &SignatureVerifier{
pubKey: pk,
}, nil
}
// verifySignature verifies that the passed in signature over data was created by our PublicKey.
// Currently, only SHA256 is supported as a HashAlgorithm, and only ECDSA and RSA signatures are supported.
func (s SignatureVerifier) verifySignature(data []byte, sig DigitallySigned) error {
if sig.HashAlgorithm != SHA256 {
return fmt.Errorf("unsupported HashAlgorithm in signature: %v", sig.HashAlgorithm)
}
hasherType := crypto.SHA256
hasher := hasherType.New()
if _, err := hasher.Write(data); err != nil {
return fmt.Errorf("failed to write to hasher: %v", err)
}
hash := hasher.Sum([]byte{})
switch sig.SignatureAlgorithm {
case RSA:
rsaKey, ok := s.pubKey.(*rsa.PublicKey)
if !ok {
return fmt.Errorf("cannot verify RSA signature with %T key", s.pubKey)
}
if err := rsa.VerifyPKCS1v15(rsaKey, hasherType, hash, sig.Signature); err != nil {
return fmt.Errorf("failed to verify rsa signature: %v", err)
}
case ECDSA:
ecdsaKey, ok := s.pubKey.(*ecdsa.PublicKey)
if !ok {
return fmt.Errorf("cannot verify ECDSA signature with %T key", s.pubKey)
}
var ecdsaSig struct {
R, S *big.Int
}
rest, err := asn1.Unmarshal(sig.Signature, &ecdsaSig)
if err != nil {
return fmt.Errorf("failed to unmarshal ECDSA signature: %v", err)
}
if len(rest) != 0 {
log.Printf("Garbage following signature %v", rest)
}
if !ecdsa.Verify(ecdsaKey, hash, ecdsaSig.R, ecdsaSig.S) {
return errors.New("failed to verify ecdsa signature")
}
default:
return fmt.Errorf("unsupported signature type %v", sig.SignatureAlgorithm)
}
return nil
}
// VerifySCTSignature verifies that the SCT's signature is valid for the given LogEntry
func (s SignatureVerifier) VerifySCTSignature(sct SignedCertificateTimestamp, entry LogEntry) error {
sctData, err := SerializeSCTSignatureInput(sct, entry)
if err != nil {
return err
}
return s.verifySignature(sctData, sct.Signature)
}
// VerifySTHSignature verifies that the STH's signature is valid.
func (s SignatureVerifier) VerifySTHSignature(sth SignedTreeHead) error {
sthData, err := SerializeSTHSignatureInput(sth)
if err != nil {
return err
}
return s.verifySignature(sthData, sth.TreeHeadSignature)
}

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package ct
import (
"bytes"
"crypto/sha256"
"encoding/base64"
"encoding/json"
"fmt"
"github.com/google/certificate-transparency/go/x509"
)
const (
issuerKeyHashLength = 32
)
///////////////////////////////////////////////////////////////////////////////
// The following structures represent those outlined in the RFC6962 document:
///////////////////////////////////////////////////////////////////////////////
// LogEntryType represents the LogEntryType enum from section 3.1 of the RFC:
// enum { x509_entry(0), precert_entry(1), (65535) } LogEntryType;
type LogEntryType uint16
func (e LogEntryType) String() string {
switch e {
case X509LogEntryType:
return "X509LogEntryType"
case PrecertLogEntryType:
return "PrecertLogEntryType"
}
panic(fmt.Sprintf("No string defined for LogEntryType constant value %d", e))
}
// LogEntryType constants, see section 3.1 of RFC6962.
const (
X509LogEntryType LogEntryType = 0
PrecertLogEntryType LogEntryType = 1
)
// MerkleLeafType represents the MerkleLeafType enum from section 3.4 of the
// RFC: enum { timestamped_entry(0), (255) } MerkleLeafType;
type MerkleLeafType uint8
func (m MerkleLeafType) String() string {
switch m {
case TimestampedEntryLeafType:
return "TimestampedEntryLeafType"
default:
return fmt.Sprintf("UnknownLeafType(%d)", m)
}
}
// MerkleLeafType constants, see section 3.4 of the RFC.
const (
TimestampedEntryLeafType MerkleLeafType = 0 // Entry type for an SCT
)
// Version represents the Version enum from section 3.2 of the RFC:
// enum { v1(0), (255) } Version;
type Version uint8
func (v Version) String() string {
switch v {
case V1:
return "V1"
default:
return fmt.Sprintf("UnknownVersion(%d)", v)
}
}
// CT Version constants, see section 3.2 of the RFC.
const (
V1 Version = 0
)
// SignatureType differentiates STH signatures from SCT signatures, see RFC
// section 3.2
type SignatureType uint8
func (st SignatureType) String() string {
switch st {
case CertificateTimestampSignatureType:
return "CertificateTimestamp"
case TreeHashSignatureType:
return "TreeHash"
default:
return fmt.Sprintf("UnknownSignatureType(%d)", st)
}
}
// SignatureType constants, see RFC section 3.2
const (
CertificateTimestampSignatureType SignatureType = 0
TreeHashSignatureType SignatureType = 1
)
// ASN1Cert type for holding the raw DER bytes of an ASN.1 Certificate
// (section 3.1)
type ASN1Cert []byte
// PreCert represents a Precertificate (section 3.2)
type PreCert struct {
IssuerKeyHash [issuerKeyHashLength]byte
TBSCertificate []byte
}
// CTExtensions is a representation of the raw bytes of any CtExtension
// structure (see section 3.2)
type CTExtensions []byte
// MerkleTreeNode represents an internal node in the CT tree
type MerkleTreeNode []byte
// ConsistencyProof represents a CT consistency proof (see sections 2.1.2 and
// 4.4)
type ConsistencyProof []MerkleTreeNode
// AuditPath represents a CT inclusion proof (see sections 2.1.1 and 4.5)
type AuditPath []MerkleTreeNode
// LeafInput represents a serialized MerkleTreeLeaf structure
type LeafInput []byte
// HashAlgorithm from the DigitallySigned struct
type HashAlgorithm byte
// HashAlgorithm constants
const (
None HashAlgorithm = 0
MD5 HashAlgorithm = 1
SHA1 HashAlgorithm = 2
SHA224 HashAlgorithm = 3
SHA256 HashAlgorithm = 4
SHA384 HashAlgorithm = 5
SHA512 HashAlgorithm = 6
)
func (h HashAlgorithm) String() string {
switch h {
case None:
return "None"
case MD5:
return "MD5"
case SHA1:
return "SHA1"
case SHA224:
return "SHA224"
case SHA256:
return "SHA256"
case SHA384:
return "SHA384"
case SHA512:
return "SHA512"
default:
return fmt.Sprintf("UNKNOWN(%d)", h)
}
}
// SignatureAlgorithm from the the DigitallySigned struct
type SignatureAlgorithm byte
// SignatureAlgorithm constants
const (
Anonymous SignatureAlgorithm = 0
RSA SignatureAlgorithm = 1
DSA SignatureAlgorithm = 2
ECDSA SignatureAlgorithm = 3
)
func (s SignatureAlgorithm) String() string {
switch s {
case Anonymous:
return "Anonymous"
case RSA:
return "RSA"
case DSA:
return "DSA"
case ECDSA:
return "ECDSA"
default:
return fmt.Sprintf("UNKNOWN(%d)", s)
}
}
// DigitallySigned represents an RFC5246 DigitallySigned structure
type DigitallySigned struct {
HashAlgorithm HashAlgorithm
SignatureAlgorithm SignatureAlgorithm
Signature []byte
}
// FromBase64String populates the DigitallySigned structure from the base64 data passed in.
// Returns an error if the base64 data is invalid.
func (d *DigitallySigned) FromBase64String(b64 string) error {
raw, err := base64.StdEncoding.DecodeString(b64)
if err != nil {
return fmt.Errorf("failed to unbase64 DigitallySigned: %v", err)
}
ds, err := UnmarshalDigitallySigned(bytes.NewReader(raw))
if err != nil {
return fmt.Errorf("failed to unmarshal DigitallySigned: %v", err)
}
*d = *ds
return nil
}
// Base64String returns the base64 representation of the DigitallySigned struct.
func (d DigitallySigned) Base64String() (string, error) {
b, err := MarshalDigitallySigned(d)
if err != nil {
return "", err
}
return base64.StdEncoding.EncodeToString(b), nil
}
// MarshalJSON implements the json.Marshaller interface.
func (d DigitallySigned) MarshalJSON() ([]byte, error) {
b64, err := d.Base64String()
if err != nil {
return []byte{}, err
}
return []byte(`"` + b64 + `"`), nil
}
// UnmarshalJSON implements the json.Unmarshaler interface.
func (d *DigitallySigned) UnmarshalJSON(b []byte) error {
var content string
if err := json.Unmarshal(b, &content); err != nil {
return fmt.Errorf("failed to unmarshal DigitallySigned: %v", err)
}
return d.FromBase64String(content)
}
// LogEntry represents the contents of an entry in a CT log, see section 3.1.
type LogEntry struct {
Index int64
Leaf MerkleTreeLeaf
X509Cert *x509.Certificate
Precert *Precertificate
Chain []ASN1Cert
}
// SHA256Hash represents the output from the SHA256 hash function.
type SHA256Hash [sha256.Size]byte
// FromBase64String populates the SHA256 struct with the contents of the base64 data passed in.
func (s *SHA256Hash) FromBase64String(b64 string) error {
bs, err := base64.StdEncoding.DecodeString(b64)
if err != nil {
return fmt.Errorf("failed to unbase64 LogID: %v", err)
}
if len(bs) != sha256.Size {
return fmt.Errorf("invalid SHA256 length, expected 32 but got %d", len(bs))
}
copy(s[:], bs)
return nil
}
// Base64String returns the base64 representation of this SHA256Hash.
func (s SHA256Hash) Base64String() string {
return base64.StdEncoding.EncodeToString(s[:])
}
// MarshalJSON implements the json.Marshaller interface for SHA256Hash.
func (s SHA256Hash) MarshalJSON() ([]byte, error) {
return []byte(`"` + s.Base64String() + `"`), nil
}
// UnmarshalJSON implements the json.Unmarshaller interface.
func (s *SHA256Hash) UnmarshalJSON(b []byte) error {
var content string
if err := json.Unmarshal(b, &content); err != nil {
return fmt.Errorf("failed to unmarshal SHA256Hash: %v", err)
}
return s.FromBase64String(content)
}
// SignedTreeHead represents the structure returned by the get-sth CT method
// after base64 decoding. See sections 3.5 and 4.3 in the RFC)
type SignedTreeHead struct {
Version Version `json:"sth_version"` // The version of the protocol to which the STH conforms
TreeSize uint64 `json:"tree_size"` // The number of entries in the new tree
Timestamp uint64 `json:"timestamp"` // The time at which the STH was created
SHA256RootHash SHA256Hash `json:"sha256_root_hash"` // The root hash of the log's Merkle tree
TreeHeadSignature DigitallySigned `json:"tree_head_signature"` // The Log's signature for this STH (see RFC section 3.5)
LogID SHA256Hash `json:"log_id"` // The SHA256 hash of the log's public key
}
// SignedCertificateTimestamp represents the structure returned by the
// add-chain and add-pre-chain methods after base64 decoding. (see RFC sections
// 3.2 ,4.1 and 4.2)
type SignedCertificateTimestamp struct {
SCTVersion Version // The version of the protocol to which the SCT conforms
LogID SHA256Hash // the SHA-256 hash of the log's public key, calculated over
// the DER encoding of the key represented as SubjectPublicKeyInfo.
Timestamp uint64 // Timestamp (in ms since unix epoc) at which the SCT was issued
Extensions CTExtensions // For future extensions to the protocol
Signature DigitallySigned // The Log's signature for this SCT
}
func (s SignedCertificateTimestamp) String() string {
return fmt.Sprintf("{Version:%d LogId:%s Timestamp:%d Extensions:'%s' Signature:%v}", s.SCTVersion,
base64.StdEncoding.EncodeToString(s.LogID[:]),
s.Timestamp,
s.Extensions,
s.Signature)
}
// TimestampedEntry is part of the MerkleTreeLeaf structure.
// See RFC section 3.4
type TimestampedEntry struct {
Timestamp uint64
EntryType LogEntryType
X509Entry ASN1Cert
PrecertEntry PreCert
Extensions CTExtensions
}
// MerkleTreeLeaf represents the deserialized sructure of the hash input for the
// leaves of a log's Merkle tree. See RFC section 3.4
type MerkleTreeLeaf struct {
Version Version // the version of the protocol to which the MerkleTreeLeaf corresponds
LeafType MerkleLeafType // The type of the leaf input, currently only TimestampedEntry can exist
TimestampedEntry TimestampedEntry // The entry data itself
}
// Precertificate represents the parsed CT Precertificate structure.
type Precertificate struct {
// Raw DER bytes of the precert
Raw []byte
// SHA256 hash of the issuing key
IssuerKeyHash [issuerKeyHashLength]byte
// Parsed TBSCertificate structure (held in an x509.Certificate for ease of
// access.
TBSCertificate x509.Certificate
}
// X509Certificate returns the X.509 Certificate contained within the
// MerkleTreeLeaf.
// Returns a pointer to an x509.Certificate or a non-nil error.
func (m *MerkleTreeLeaf) X509Certificate() (*x509.Certificate, error) {
return x509.ParseCertificate(m.TimestampedEntry.X509Entry)
}
type sctError int
// Preallocate errors for performance
var (
ErrInvalidVersion error = sctError(1)
ErrNotEnoughBuffer error = sctError(2)
)
func (e sctError) Error() string {
switch e {
case ErrInvalidVersion:
return "invalid SCT version detected"
case ErrNotEnoughBuffer:
return "provided buffer was too small"
default:
return "unknown error"
}
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x509
import (
"encoding/pem"
)
// CertPool is a set of certificates.
type CertPool struct {
bySubjectKeyId map[string][]int
byName map[string][]int
certs []*Certificate
}
// NewCertPool returns a new, empty CertPool.
func NewCertPool() *CertPool {
return &CertPool{
make(map[string][]int),
make(map[string][]int),
nil,
}
}
// findVerifiedParents attempts to find certificates in s which have signed the
// given certificate. If any candidates were rejected then errCert will be set
// to one of them, arbitrarily, and err will contain the reason that it was
// rejected.
func (s *CertPool) findVerifiedParents(cert *Certificate) (parents []int, errCert *Certificate, err error) {
if s == nil {
return
}
var candidates []int
if len(cert.AuthorityKeyId) > 0 {
candidates = s.bySubjectKeyId[string(cert.AuthorityKeyId)]
}
if len(candidates) == 0 {
candidates = s.byName[string(cert.RawIssuer)]
}
for _, c := range candidates {
if err = cert.CheckSignatureFrom(s.certs[c]); err == nil {
parents = append(parents, c)
} else {
errCert = s.certs[c]
}
}
return
}
// AddCert adds a certificate to a pool.
func (s *CertPool) AddCert(cert *Certificate) {
if cert == nil {
panic("adding nil Certificate to CertPool")
}
// Check that the certificate isn't being added twice.
for _, c := range s.certs {
if c.Equal(cert) {
return
}
}
n := len(s.certs)
s.certs = append(s.certs, cert)
if len(cert.SubjectKeyId) > 0 {
keyId := string(cert.SubjectKeyId)
s.bySubjectKeyId[keyId] = append(s.bySubjectKeyId[keyId], n)
}
name := string(cert.RawSubject)
s.byName[name] = append(s.byName[name], n)
}
// AppendCertsFromPEM attempts to parse a series of PEM encoded certificates.
// It appends any certificates found to s and returns true if any certificates
// were successfully parsed.
//
// On many Linux systems, /etc/ssl/cert.pem will contain the system wide set
// of root CAs in a format suitable for this function.
func (s *CertPool) AppendCertsFromPEM(pemCerts []byte) (ok bool) {
for len(pemCerts) > 0 {
var block *pem.Block
block, pemCerts = pem.Decode(pemCerts)
if block == nil {
break
}
if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
continue
}
cert, err := ParseCertificate(block.Bytes)
if err != nil {
continue
}
s.AddCert(cert)
ok = true
}
return
}
// Subjects returns a list of the DER-encoded subjects of
// all of the certificates in the pool.
func (s *CertPool) Subjects() (res [][]byte) {
res = make([][]byte, len(s.certs))
for i, c := range s.certs {
res[i] = c.RawSubject
}
return
}

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x509
// RFC 1423 describes the encryption of PEM blocks. The algorithm used to
// generate a key from the password was derived by looking at the OpenSSL
// implementation.
import (
"crypto/aes"
"crypto/cipher"
"crypto/des"
"crypto/md5"
"encoding/hex"
"encoding/pem"
"errors"
"io"
"strings"
)
type PEMCipher int
// Possible values for the EncryptPEMBlock encryption algorithm.
const (
_ PEMCipher = iota
PEMCipherDES
PEMCipher3DES
PEMCipherAES128
PEMCipherAES192
PEMCipherAES256
)
// rfc1423Algo holds a method for enciphering a PEM block.
type rfc1423Algo struct {
cipher PEMCipher
name string
cipherFunc func(key []byte) (cipher.Block, error)
keySize int
blockSize int
}
// rfc1423Algos holds a slice of the possible ways to encrypt a PEM
// block. The ivSize numbers were taken from the OpenSSL source.
var rfc1423Algos = []rfc1423Algo{{
cipher: PEMCipherDES,
name: "DES-CBC",
cipherFunc: des.NewCipher,
keySize: 8,
blockSize: des.BlockSize,
}, {
cipher: PEMCipher3DES,
name: "DES-EDE3-CBC",
cipherFunc: des.NewTripleDESCipher,
keySize: 24,
blockSize: des.BlockSize,
}, {
cipher: PEMCipherAES128,
name: "AES-128-CBC",
cipherFunc: aes.NewCipher,
keySize: 16,
blockSize: aes.BlockSize,
}, {
cipher: PEMCipherAES192,
name: "AES-192-CBC",
cipherFunc: aes.NewCipher,
keySize: 24,
blockSize: aes.BlockSize,
}, {
cipher: PEMCipherAES256,
name: "AES-256-CBC",
cipherFunc: aes.NewCipher,
keySize: 32,
blockSize: aes.BlockSize,
},
}
// deriveKey uses a key derivation function to stretch the password into a key
// with the number of bits our cipher requires. This algorithm was derived from
// the OpenSSL source.
func (c rfc1423Algo) deriveKey(password, salt []byte) []byte {
hash := md5.New()
out := make([]byte, c.keySize)
var digest []byte
for i := 0; i < len(out); i += len(digest) {
hash.Reset()
hash.Write(digest)
hash.Write(password)
hash.Write(salt)
digest = hash.Sum(digest[:0])
copy(out[i:], digest)
}
return out
}
// IsEncryptedPEMBlock returns if the PEM block is password encrypted.
func IsEncryptedPEMBlock(b *pem.Block) bool {
_, ok := b.Headers["DEK-Info"]
return ok
}
// IncorrectPasswordError is returned when an incorrect password is detected.
var IncorrectPasswordError = errors.New("x509: decryption password incorrect")
// DecryptPEMBlock takes a password encrypted PEM block and the password used to
// encrypt it and returns a slice of decrypted DER encoded bytes. It inspects
// the DEK-Info header to determine the algorithm used for decryption. If no
// DEK-Info header is present, an error is returned. If an incorrect password
// is detected an IncorrectPasswordError is returned.
func DecryptPEMBlock(b *pem.Block, password []byte) ([]byte, error) {
dek, ok := b.Headers["DEK-Info"]
if !ok {
return nil, errors.New("x509: no DEK-Info header in block")
}
idx := strings.Index(dek, ",")
if idx == -1 {
return nil, errors.New("x509: malformed DEK-Info header")
}
mode, hexIV := dek[:idx], dek[idx+1:]
ciph := cipherByName(mode)
if ciph == nil {
return nil, errors.New("x509: unknown encryption mode")
}
iv, err := hex.DecodeString(hexIV)
if err != nil {
return nil, err
}
if len(iv) != ciph.blockSize {
return nil, errors.New("x509: incorrect IV size")
}
// Based on the OpenSSL implementation. The salt is the first 8 bytes
// of the initialization vector.
key := ciph.deriveKey(password, iv[:8])
block, err := ciph.cipherFunc(key)
if err != nil {
return nil, err
}
data := make([]byte, len(b.Bytes))
dec := cipher.NewCBCDecrypter(block, iv)
dec.CryptBlocks(data, b.Bytes)
// Blocks are padded using a scheme where the last n bytes of padding are all
// equal to n. It can pad from 1 to blocksize bytes inclusive. See RFC 1423.
// For example:
// [x y z 2 2]
// [x y 7 7 7 7 7 7 7]
// If we detect a bad padding, we assume it is an invalid password.
dlen := len(data)
if dlen == 0 || dlen%ciph.blockSize != 0 {
return nil, errors.New("x509: invalid padding")
}
last := int(data[dlen-1])
if dlen < last {
return nil, IncorrectPasswordError
}
if last == 0 || last > ciph.blockSize {
return nil, IncorrectPasswordError
}
for _, val := range data[dlen-last:] {
if int(val) != last {
return nil, IncorrectPasswordError
}
}
return data[:dlen-last], nil
}
// EncryptPEMBlock returns a PEM block of the specified type holding the
// given DER-encoded data encrypted with the specified algorithm and
// password.
func EncryptPEMBlock(rand io.Reader, blockType string, data, password []byte, alg PEMCipher) (*pem.Block, error) {
ciph := cipherByKey(alg)
if ciph == nil {
return nil, errors.New("x509: unknown encryption mode")
}
iv := make([]byte, ciph.blockSize)
if _, err := io.ReadFull(rand, iv); err != nil {
return nil, errors.New("x509: cannot generate IV: " + err.Error())
}
// The salt is the first 8 bytes of the initialization vector,
// matching the key derivation in DecryptPEMBlock.
key := ciph.deriveKey(password, iv[:8])
block, err := ciph.cipherFunc(key)
if err != nil {
return nil, err
}
enc := cipher.NewCBCEncrypter(block, iv)
pad := ciph.blockSize - len(data)%ciph.blockSize
encrypted := make([]byte, len(data), len(data)+pad)
// We could save this copy by encrypting all the whole blocks in
// the data separately, but it doesn't seem worth the additional
// code.
copy(encrypted, data)
// See RFC 1423, section 1.1
for i := 0; i < pad; i++ {
encrypted = append(encrypted, byte(pad))
}
enc.CryptBlocks(encrypted, encrypted)
return &pem.Block{
Type: blockType,
Headers: map[string]string{
"Proc-Type": "4,ENCRYPTED",
"DEK-Info": ciph.name + "," + hex.EncodeToString(iv),
},
Bytes: encrypted,
}, nil
}
func cipherByName(name string) *rfc1423Algo {
for i := range rfc1423Algos {
alg := &rfc1423Algos[i]
if alg.name == name {
return alg
}
}
return nil
}
func cipherByKey(key PEMCipher) *rfc1423Algo {
for i := range rfc1423Algos {
alg := &rfc1423Algos[i]
if alg.cipher == key {
return alg
}
}
return nil
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x509
import (
"crypto/rsa"
// START CT CHANGES
"github.com/google/certificate-transparency/go/asn1"
// END CT CHANGES
"errors"
"math/big"
)
// pkcs1PrivateKey is a structure which mirrors the PKCS#1 ASN.1 for an RSA private key.
type pkcs1PrivateKey struct {
Version int
N *big.Int
E int
D *big.Int
P *big.Int
Q *big.Int
// We ignore these values, if present, because rsa will calculate them.
Dp *big.Int `asn1:"optional"`
Dq *big.Int `asn1:"optional"`
Qinv *big.Int `asn1:"optional"`
AdditionalPrimes []pkcs1AdditionalRSAPrime `asn1:"optional,omitempty"`
}
type pkcs1AdditionalRSAPrime struct {
Prime *big.Int
// We ignore these values because rsa will calculate them.
Exp *big.Int
Coeff *big.Int
}
// ParsePKCS1PrivateKey returns an RSA private key from its ASN.1 PKCS#1 DER encoded form.
func ParsePKCS1PrivateKey(der []byte) (key *rsa.PrivateKey, err error) {
var priv pkcs1PrivateKey
rest, err := asn1.Unmarshal(der, &priv)
if len(rest) > 0 {
err = asn1.SyntaxError{Msg: "trailing data"}
return
}
if err != nil {
return
}
if priv.Version > 1 {
return nil, errors.New("x509: unsupported private key version")
}
if priv.N.Sign() <= 0 || priv.D.Sign() <= 0 || priv.P.Sign() <= 0 || priv.Q.Sign() <= 0 {
return nil, errors.New("x509: private key contains zero or negative value")
}
key = new(rsa.PrivateKey)
key.PublicKey = rsa.PublicKey{
E: priv.E,
N: priv.N,
}
key.D = priv.D
key.Primes = make([]*big.Int, 2+len(priv.AdditionalPrimes))
key.Primes[0] = priv.P
key.Primes[1] = priv.Q
for i, a := range priv.AdditionalPrimes {
if a.Prime.Sign() <= 0 {
return nil, errors.New("x509: private key contains zero or negative prime")
}
key.Primes[i+2] = a.Prime
// We ignore the other two values because rsa will calculate
// them as needed.
}
err = key.Validate()
if err != nil {
return nil, err
}
key.Precompute()
return
}
// MarshalPKCS1PrivateKey converts a private key to ASN.1 DER encoded form.
func MarshalPKCS1PrivateKey(key *rsa.PrivateKey) []byte {
key.Precompute()
version := 0
if len(key.Primes) > 2 {
version = 1
}
priv := pkcs1PrivateKey{
Version: version,
N: key.N,
E: key.PublicKey.E,
D: key.D,
P: key.Primes[0],
Q: key.Primes[1],
Dp: key.Precomputed.Dp,
Dq: key.Precomputed.Dq,
Qinv: key.Precomputed.Qinv,
}
priv.AdditionalPrimes = make([]pkcs1AdditionalRSAPrime, len(key.Precomputed.CRTValues))
for i, values := range key.Precomputed.CRTValues {
priv.AdditionalPrimes[i].Prime = key.Primes[2+i]
priv.AdditionalPrimes[i].Exp = values.Exp
priv.AdditionalPrimes[i].Coeff = values.Coeff
}
b, _ := asn1.Marshal(priv)
return b
}
// rsaPublicKey reflects the ASN.1 structure of a PKCS#1 public key.
type rsaPublicKey struct {
N *big.Int
E int
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x509
import (
// START CT CHANGES
"github.com/google/certificate-transparency/go/asn1"
"github.com/google/certificate-transparency/go/x509/pkix"
// END CT CHANGES
"errors"
"fmt"
)
// pkcs8 reflects an ASN.1, PKCS#8 PrivateKey. See
// ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-8/pkcs-8v1_2.asn
// and RFC5208.
type pkcs8 struct {
Version int
Algo pkix.AlgorithmIdentifier
PrivateKey []byte
// optional attributes omitted.
}
// ParsePKCS8PrivateKey parses an unencrypted, PKCS#8 private key. See
// http://www.rsa.com/rsalabs/node.asp?id=2130 and RFC5208.
func ParsePKCS8PrivateKey(der []byte) (key interface{}, err error) {
var privKey pkcs8
if _, err := asn1.Unmarshal(der, &privKey); err != nil {
return nil, err
}
switch {
case privKey.Algo.Algorithm.Equal(oidPublicKeyRSA):
key, err = ParsePKCS1PrivateKey(privKey.PrivateKey)
if err != nil {
return nil, errors.New("x509: failed to parse RSA private key embedded in PKCS#8: " + err.Error())
}
return key, nil
case privKey.Algo.Algorithm.Equal(oidPublicKeyECDSA):
bytes := privKey.Algo.Parameters.FullBytes
namedCurveOID := new(asn1.ObjectIdentifier)
if _, err := asn1.Unmarshal(bytes, namedCurveOID); err != nil {
namedCurveOID = nil
}
key, err = parseECPrivateKey(namedCurveOID, privKey.PrivateKey)
if err != nil {
return nil, errors.New("x509: failed to parse EC private key embedded in PKCS#8: " + err.Error())
}
return key, nil
default:
return nil, fmt.Errorf("x509: PKCS#8 wrapping contained private key with unknown algorithm: %v", privKey.Algo.Algorithm)
}
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package pkix contains shared, low level structures used for ASN.1 parsing
// and serialization of X.509 certificates, CRL and OCSP.
package pkix
import (
// START CT CHANGES
"github.com/google/certificate-transparency/go/asn1"
// END CT CHANGES
"math/big"
"time"
)
// AlgorithmIdentifier represents the ASN.1 structure of the same name. See RFC
// 5280, section 4.1.1.2.
type AlgorithmIdentifier struct {
Algorithm asn1.ObjectIdentifier
Parameters asn1.RawValue `asn1:"optional"`
}
type RDNSequence []RelativeDistinguishedNameSET
type RelativeDistinguishedNameSET []AttributeTypeAndValue
// AttributeTypeAndValue mirrors the ASN.1 structure of the same name in
// http://tools.ietf.org/html/rfc5280#section-4.1.2.4
type AttributeTypeAndValue struct {
Type asn1.ObjectIdentifier
Value interface{}
}
// Extension represents the ASN.1 structure of the same name. See RFC
// 5280, section 4.2.
type Extension struct {
Id asn1.ObjectIdentifier
Critical bool `asn1:"optional"`
Value []byte
}
// Name represents an X.509 distinguished name. This only includes the common
// elements of a DN. Additional elements in the name are ignored.
type Name struct {
Country, Organization, OrganizationalUnit []string
Locality, Province []string
StreetAddress, PostalCode []string
SerialNumber, CommonName string
Names []AttributeTypeAndValue
}
func (n *Name) FillFromRDNSequence(rdns *RDNSequence) {
for _, rdn := range *rdns {
if len(rdn) == 0 {
continue
}
atv := rdn[0]
n.Names = append(n.Names, atv)
value, ok := atv.Value.(string)
if !ok {
continue
}
t := atv.Type
if len(t) == 4 && t[0] == 2 && t[1] == 5 && t[2] == 4 {
switch t[3] {
case 3:
n.CommonName = value
case 5:
n.SerialNumber = value
case 6:
n.Country = append(n.Country, value)
case 7:
n.Locality = append(n.Locality, value)
case 8:
n.Province = append(n.Province, value)
case 9:
n.StreetAddress = append(n.StreetAddress, value)
case 10:
n.Organization = append(n.Organization, value)
case 11:
n.OrganizationalUnit = append(n.OrganizationalUnit, value)
case 17:
n.PostalCode = append(n.PostalCode, value)
}
}
}
}
var (
oidCountry = []int{2, 5, 4, 6}
oidOrganization = []int{2, 5, 4, 10}
oidOrganizationalUnit = []int{2, 5, 4, 11}
oidCommonName = []int{2, 5, 4, 3}
oidSerialNumber = []int{2, 5, 4, 5}
oidLocality = []int{2, 5, 4, 7}
oidProvince = []int{2, 5, 4, 8}
oidStreetAddress = []int{2, 5, 4, 9}
oidPostalCode = []int{2, 5, 4, 17}
)
// appendRDNs appends a relativeDistinguishedNameSET to the given RDNSequence
// and returns the new value. The relativeDistinguishedNameSET contains an
// attributeTypeAndValue for each of the given values. See RFC 5280, A.1, and
// search for AttributeTypeAndValue.
func appendRDNs(in RDNSequence, values []string, oid asn1.ObjectIdentifier) RDNSequence {
if len(values) == 0 {
return in
}
s := make([]AttributeTypeAndValue, len(values))
for i, value := range values {
s[i].Type = oid
s[i].Value = value
}
return append(in, s)
}
func (n Name) ToRDNSequence() (ret RDNSequence) {
ret = appendRDNs(ret, n.Country, oidCountry)
ret = appendRDNs(ret, n.Organization, oidOrganization)
ret = appendRDNs(ret, n.OrganizationalUnit, oidOrganizationalUnit)
ret = appendRDNs(ret, n.Locality, oidLocality)
ret = appendRDNs(ret, n.Province, oidProvince)
ret = appendRDNs(ret, n.StreetAddress, oidStreetAddress)
ret = appendRDNs(ret, n.PostalCode, oidPostalCode)
if len(n.CommonName) > 0 {
ret = appendRDNs(ret, []string{n.CommonName}, oidCommonName)
}
if len(n.SerialNumber) > 0 {
ret = appendRDNs(ret, []string{n.SerialNumber}, oidSerialNumber)
}
return ret
}
// CertificateList represents the ASN.1 structure of the same name. See RFC
// 5280, section 5.1. Use Certificate.CheckCRLSignature to verify the
// signature.
type CertificateList struct {
TBSCertList TBSCertificateList
SignatureAlgorithm AlgorithmIdentifier
SignatureValue asn1.BitString
}
// HasExpired reports whether now is past the expiry time of certList.
func (certList *CertificateList) HasExpired(now time.Time) bool {
return now.After(certList.TBSCertList.NextUpdate)
}
// TBSCertificateList represents the ASN.1 structure of the same name. See RFC
// 5280, section 5.1.
type TBSCertificateList struct {
Raw asn1.RawContent
Version int `asn1:"optional,default:2"`
Signature AlgorithmIdentifier
Issuer RDNSequence
ThisUpdate time.Time
NextUpdate time.Time
RevokedCertificates []RevokedCertificate `asn1:"optional"`
Extensions []Extension `asn1:"tag:0,optional,explicit"`
}
// RevokedCertificate represents the ASN.1 structure of the same name. See RFC
// 5280, section 5.1.
type RevokedCertificate struct {
SerialNumber *big.Int
RevocationTime time.Time
Extensions []Extension `asn1:"optional"`
}

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x509
import "sync"
var (
once sync.Once
systemRoots *CertPool
)
func systemRootsPool() *CertPool {
once.Do(initSystemRoots)
return systemRoots
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build darwin,cgo
package x509
/*
#cgo CFLAGS: -mmacosx-version-min=10.6 -D__MAC_OS_X_VERSION_MAX_ALLOWED=1060
#cgo LDFLAGS: -framework CoreFoundation -framework Security
#include <CoreFoundation/CoreFoundation.h>
#include <Security/Security.h>
// FetchPEMRootsCTX509 fetches the system's list of trusted X.509 root certificates.
//
// On success it returns 0 and fills pemRoots with a CFDataRef that contains the extracted root
// certificates of the system. On failure, the function returns -1.
//
// Note: The CFDataRef returned in pemRoots must be released (using CFRelease) after
// we've consumed its content.
int FetchPEMRootsCTX509(CFDataRef *pemRoots) {
if (pemRoots == NULL) {
return -1;
}
CFArrayRef certs = NULL;
OSStatus err = SecTrustCopyAnchorCertificates(&certs);
if (err != noErr) {
return -1;
}
CFMutableDataRef combinedData = CFDataCreateMutable(kCFAllocatorDefault, 0);
int i, ncerts = CFArrayGetCount(certs);
for (i = 0; i < ncerts; i++) {
CFDataRef data = NULL;
SecCertificateRef cert = (SecCertificateRef)CFArrayGetValueAtIndex(certs, i);
if (cert == NULL) {
continue;
}
// Note: SecKeychainItemExport is deprecated as of 10.7 in favor of SecItemExport.
// Once we support weak imports via cgo we should prefer that, and fall back to this
// for older systems.
err = SecKeychainItemExport(cert, kSecFormatX509Cert, kSecItemPemArmour, NULL, &data);
if (err != noErr) {
continue;
}
if (data != NULL) {
CFDataAppendBytes(combinedData, CFDataGetBytePtr(data), CFDataGetLength(data));
CFRelease(data);
}
}
CFRelease(certs);
*pemRoots = combinedData;
return 0;
}
*/
import "C"
import "unsafe"
func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
return nil, nil
}
func initSystemRoots() {
roots := NewCertPool()
var data C.CFDataRef = nil
err := C.FetchPEMRootsCTX509(&data)
if err == -1 {
return
}
defer C.CFRelease(C.CFTypeRef(data))
buf := C.GoBytes(unsafe.Pointer(C.CFDataGetBytePtr(data)), C.int(C.CFDataGetLength(data)))
roots.AppendCertsFromPEM(buf)
systemRoots = roots
}

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build plan9
package x509
import "io/ioutil"
// Possible certificate files; stop after finding one.
var certFiles = []string{
"/sys/lib/tls/ca.pem",
}
func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
return nil, nil
}
func initSystemRoots() {
roots := NewCertPool()
for _, file := range certFiles {
data, err := ioutil.ReadFile(file)
if err == nil {
roots.AppendCertsFromPEM(data)
systemRoots = roots
return
}
}
// All of the files failed to load. systemRoots will be nil which will
// trigger a specific error at verification time.
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build darwin,!cgo
package x509
func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
return nil, nil
}
func initSystemRoots() {
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build dragonfly freebsd linux openbsd netbsd
package x509
import "io/ioutil"
// Possible certificate files; stop after finding one.
var certFiles = []string{
"/etc/ssl/certs/ca-certificates.crt", // Debian/Ubuntu/Gentoo etc.
"/etc/pki/tls/certs/ca-bundle.crt", // Fedora/RHEL
"/etc/ssl/ca-bundle.pem", // OpenSUSE
"/etc/ssl/cert.pem", // OpenBSD
"/usr/local/share/certs/ca-root-nss.crt", // FreeBSD/DragonFly
}
func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
return nil, nil
}
func initSystemRoots() {
roots := NewCertPool()
for _, file := range certFiles {
data, err := ioutil.ReadFile(file)
if err == nil {
roots.AppendCertsFromPEM(data)
systemRoots = roots
return
}
}
// All of the files failed to load. systemRoots will be nil which will
// trigger a specific error at verification time.
}

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x509
import (
"errors"
"syscall"
"unsafe"
)
// Creates a new *syscall.CertContext representing the leaf certificate in an in-memory
// certificate store containing itself and all of the intermediate certificates specified
// in the opts.Intermediates CertPool.
//
// A pointer to the in-memory store is available in the returned CertContext's Store field.
// The store is automatically freed when the CertContext is freed using
// syscall.CertFreeCertificateContext.
func createStoreContext(leaf *Certificate, opts *VerifyOptions) (*syscall.CertContext, error) {
var storeCtx *syscall.CertContext
leafCtx, err := syscall.CertCreateCertificateContext(syscall.X509_ASN_ENCODING|syscall.PKCS_7_ASN_ENCODING, &leaf.Raw[0], uint32(len(leaf.Raw)))
if err != nil {
return nil, err
}
defer syscall.CertFreeCertificateContext(leafCtx)
handle, err := syscall.CertOpenStore(syscall.CERT_STORE_PROV_MEMORY, 0, 0, syscall.CERT_STORE_DEFER_CLOSE_UNTIL_LAST_FREE_FLAG, 0)
if err != nil {
return nil, err
}
defer syscall.CertCloseStore(handle, 0)
err = syscall.CertAddCertificateContextToStore(handle, leafCtx, syscall.CERT_STORE_ADD_ALWAYS, &storeCtx)
if err != nil {
return nil, err
}
if opts.Intermediates != nil {
for _, intermediate := range opts.Intermediates.certs {
ctx, err := syscall.CertCreateCertificateContext(syscall.X509_ASN_ENCODING|syscall.PKCS_7_ASN_ENCODING, &intermediate.Raw[0], uint32(len(intermediate.Raw)))
if err != nil {
return nil, err
}
err = syscall.CertAddCertificateContextToStore(handle, ctx, syscall.CERT_STORE_ADD_ALWAYS, nil)
syscall.CertFreeCertificateContext(ctx)
if err != nil {
return nil, err
}
}
}
return storeCtx, nil
}
// extractSimpleChain extracts the final certificate chain from a CertSimpleChain.
func extractSimpleChain(simpleChain **syscall.CertSimpleChain, count int) (chain []*Certificate, err error) {
if simpleChain == nil || count == 0 {
return nil, errors.New("x509: invalid simple chain")
}
simpleChains := (*[1 << 20]*syscall.CertSimpleChain)(unsafe.Pointer(simpleChain))[:]
lastChain := simpleChains[count-1]
elements := (*[1 << 20]*syscall.CertChainElement)(unsafe.Pointer(lastChain.Elements))[:]
for i := 0; i < int(lastChain.NumElements); i++ {
// Copy the buf, since ParseCertificate does not create its own copy.
cert := elements[i].CertContext
encodedCert := (*[1 << 20]byte)(unsafe.Pointer(cert.EncodedCert))[:]
buf := make([]byte, cert.Length)
copy(buf, encodedCert[:])
parsedCert, err := ParseCertificate(buf)
if err != nil {
return nil, err
}
chain = append(chain, parsedCert)
}
return chain, nil
}
// checkChainTrustStatus checks the trust status of the certificate chain, translating
// any errors it finds into Go errors in the process.
func checkChainTrustStatus(c *Certificate, chainCtx *syscall.CertChainContext) error {
if chainCtx.TrustStatus.ErrorStatus != syscall.CERT_TRUST_NO_ERROR {
status := chainCtx.TrustStatus.ErrorStatus
switch status {
case syscall.CERT_TRUST_IS_NOT_TIME_VALID:
return CertificateInvalidError{c, Expired}
default:
return UnknownAuthorityError{c, nil, nil}
}
}
return nil
}
// checkChainSSLServerPolicy checks that the certificate chain in chainCtx is valid for
// use as a certificate chain for a SSL/TLS server.
func checkChainSSLServerPolicy(c *Certificate, chainCtx *syscall.CertChainContext, opts *VerifyOptions) error {
servernamep, err := syscall.UTF16PtrFromString(opts.DNSName)
if err != nil {
return err
}
sslPara := &syscall.SSLExtraCertChainPolicyPara{
AuthType: syscall.AUTHTYPE_SERVER,
ServerName: servernamep,
}
sslPara.Size = uint32(unsafe.Sizeof(*sslPara))
para := &syscall.CertChainPolicyPara{
ExtraPolicyPara: uintptr(unsafe.Pointer(sslPara)),
}
para.Size = uint32(unsafe.Sizeof(*para))
status := syscall.CertChainPolicyStatus{}
err = syscall.CertVerifyCertificateChainPolicy(syscall.CERT_CHAIN_POLICY_SSL, chainCtx, para, &status)
if err != nil {
return err
}
// TODO(mkrautz): use the lChainIndex and lElementIndex fields
// of the CertChainPolicyStatus to provide proper context, instead
// using c.
if status.Error != 0 {
switch status.Error {
case syscall.CERT_E_EXPIRED:
return CertificateInvalidError{c, Expired}
case syscall.CERT_E_CN_NO_MATCH:
return HostnameError{c, opts.DNSName}
case syscall.CERT_E_UNTRUSTEDROOT:
return UnknownAuthorityError{c, nil, nil}
default:
return UnknownAuthorityError{c, nil, nil}
}
}
return nil
}
// systemVerify is like Verify, except that it uses CryptoAPI calls
// to build certificate chains and verify them.
func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
hasDNSName := opts != nil && len(opts.DNSName) > 0
storeCtx, err := createStoreContext(c, opts)
if err != nil {
return nil, err
}
defer syscall.CertFreeCertificateContext(storeCtx)
para := new(syscall.CertChainPara)
para.Size = uint32(unsafe.Sizeof(*para))
// If there's a DNSName set in opts, assume we're verifying
// a certificate from a TLS server.
if hasDNSName {
oids := []*byte{
&syscall.OID_PKIX_KP_SERVER_AUTH[0],
// Both IE and Chrome allow certificates with
// Server Gated Crypto as well. Some certificates
// in the wild require them.
&syscall.OID_SERVER_GATED_CRYPTO[0],
&syscall.OID_SGC_NETSCAPE[0],
}
para.RequestedUsage.Type = syscall.USAGE_MATCH_TYPE_OR
para.RequestedUsage.Usage.Length = uint32(len(oids))
para.RequestedUsage.Usage.UsageIdentifiers = &oids[0]
} else {
para.RequestedUsage.Type = syscall.USAGE_MATCH_TYPE_AND
para.RequestedUsage.Usage.Length = 0
para.RequestedUsage.Usage.UsageIdentifiers = nil
}
var verifyTime *syscall.Filetime
if opts != nil && !opts.CurrentTime.IsZero() {
ft := syscall.NsecToFiletime(opts.CurrentTime.UnixNano())
verifyTime = &ft
}
// CertGetCertificateChain will traverse Windows's root stores
// in an attempt to build a verified certificate chain. Once
// it has found a verified chain, it stops. MSDN docs on
// CERT_CHAIN_CONTEXT:
//
// When a CERT_CHAIN_CONTEXT is built, the first simple chain
// begins with an end certificate and ends with a self-signed
// certificate. If that self-signed certificate is not a root
// or otherwise trusted certificate, an attempt is made to
// build a new chain. CTLs are used to create the new chain
// beginning with the self-signed certificate from the original
// chain as the end certificate of the new chain. This process
// continues building additional simple chains until the first
// self-signed certificate is a trusted certificate or until
// an additional simple chain cannot be built.
//
// The result is that we'll only get a single trusted chain to
// return to our caller.
var chainCtx *syscall.CertChainContext
err = syscall.CertGetCertificateChain(syscall.Handle(0), storeCtx, verifyTime, storeCtx.Store, para, 0, 0, &chainCtx)
if err != nil {
return nil, err
}
defer syscall.CertFreeCertificateChain(chainCtx)
err = checkChainTrustStatus(c, chainCtx)
if err != nil {
return nil, err
}
if hasDNSName {
err = checkChainSSLServerPolicy(c, chainCtx, opts)
if err != nil {
return nil, err
}
}
chain, err := extractSimpleChain(chainCtx.Chains, int(chainCtx.ChainCount))
if err != nil {
return nil, err
}
chains = append(chains, chain)
return chains, nil
}
func initSystemRoots() {
}

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@@ -0,0 +1,85 @@
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x509
import (
"crypto/ecdsa"
"crypto/elliptic"
// START CT CHANGES
"github.com/google/certificate-transparency/go/asn1"
// START CT CHANGES
"errors"
"fmt"
"math/big"
)
const ecPrivKeyVersion = 1
// ecPrivateKey reflects an ASN.1 Elliptic Curve Private Key Structure.
// References:
// RFC5915
// SEC1 - http://www.secg.org/download/aid-780/sec1-v2.pdf
// Per RFC5915 the NamedCurveOID is marked as ASN.1 OPTIONAL, however in
// most cases it is not.
type ecPrivateKey struct {
Version int
PrivateKey []byte
NamedCurveOID asn1.ObjectIdentifier `asn1:"optional,explicit,tag:0"`
PublicKey asn1.BitString `asn1:"optional,explicit,tag:1"`
}
// ParseECPrivateKey parses an ASN.1 Elliptic Curve Private Key Structure.
func ParseECPrivateKey(der []byte) (key *ecdsa.PrivateKey, err error) {
return parseECPrivateKey(nil, der)
}
// MarshalECPrivateKey marshals an EC private key into ASN.1, DER format.
func MarshalECPrivateKey(key *ecdsa.PrivateKey) ([]byte, error) {
oid, ok := oidFromNamedCurve(key.Curve)
if !ok {
return nil, errors.New("x509: unknown elliptic curve")
}
return asn1.Marshal(ecPrivateKey{
Version: 1,
PrivateKey: key.D.Bytes(),
NamedCurveOID: oid,
PublicKey: asn1.BitString{Bytes: elliptic.Marshal(key.Curve, key.X, key.Y)},
})
}
// parseECPrivateKey parses an ASN.1 Elliptic Curve Private Key Structure.
// The OID for the named curve may be provided from another source (such as
// the PKCS8 container) - if it is provided then use this instead of the OID
// that may exist in the EC private key structure.
func parseECPrivateKey(namedCurveOID *asn1.ObjectIdentifier, der []byte) (key *ecdsa.PrivateKey, err error) {
var privKey ecPrivateKey
if _, err := asn1.Unmarshal(der, &privKey); err != nil {
return nil, errors.New("x509: failed to parse EC private key: " + err.Error())
}
if privKey.Version != ecPrivKeyVersion {
return nil, fmt.Errorf("x509: unknown EC private key version %d", privKey.Version)
}
var curve elliptic.Curve
if namedCurveOID != nil {
curve = namedCurveFromOID(*namedCurveOID)
} else {
curve = namedCurveFromOID(privKey.NamedCurveOID)
}
if curve == nil {
return nil, errors.New("x509: unknown elliptic curve")
}
k := new(big.Int).SetBytes(privKey.PrivateKey)
if k.Cmp(curve.Params().N) >= 0 {
return nil, errors.New("x509: invalid elliptic curve private key value")
}
priv := new(ecdsa.PrivateKey)
priv.Curve = curve
priv.D = k
priv.X, priv.Y = curve.ScalarBaseMult(privKey.PrivateKey)
return priv, nil
}

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@@ -0,0 +1,476 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x509
import (
"fmt"
"net"
"runtime"
"strings"
"time"
"unicode/utf8"
)
type InvalidReason int
const (
// NotAuthorizedToSign results when a certificate is signed by another
// which isn't marked as a CA certificate.
NotAuthorizedToSign InvalidReason = iota
// Expired results when a certificate has expired, based on the time
// given in the VerifyOptions.
Expired
// CANotAuthorizedForThisName results when an intermediate or root
// certificate has a name constraint which doesn't include the name
// being checked.
CANotAuthorizedForThisName
// TooManyIntermediates results when a path length constraint is
// violated.
TooManyIntermediates
// IncompatibleUsage results when the certificate's key usage indicates
// that it may only be used for a different purpose.
IncompatibleUsage
)
// CertificateInvalidError results when an odd error occurs. Users of this
// library probably want to handle all these errors uniformly.
type CertificateInvalidError struct {
Cert *Certificate
Reason InvalidReason
}
func (e CertificateInvalidError) Error() string {
switch e.Reason {
case NotAuthorizedToSign:
return "x509: certificate is not authorized to sign other certificates"
case Expired:
return "x509: certificate has expired or is not yet valid"
case CANotAuthorizedForThisName:
return "x509: a root or intermediate certificate is not authorized to sign in this domain"
case TooManyIntermediates:
return "x509: too many intermediates for path length constraint"
case IncompatibleUsage:
return "x509: certificate specifies an incompatible key usage"
}
return "x509: unknown error"
}
// HostnameError results when the set of authorized names doesn't match the
// requested name.
type HostnameError struct {
Certificate *Certificate
Host string
}
func (h HostnameError) Error() string {
c := h.Certificate
var valid string
if ip := net.ParseIP(h.Host); ip != nil {
// Trying to validate an IP
if len(c.IPAddresses) == 0 {
return "x509: cannot validate certificate for " + h.Host + " because it doesn't contain any IP SANs"
}
for _, san := range c.IPAddresses {
if len(valid) > 0 {
valid += ", "
}
valid += san.String()
}
} else {
if len(c.DNSNames) > 0 {
valid = strings.Join(c.DNSNames, ", ")
} else {
valid = c.Subject.CommonName
}
}
return "x509: certificate is valid for " + valid + ", not " + h.Host
}
// UnknownAuthorityError results when the certificate issuer is unknown
type UnknownAuthorityError struct {
cert *Certificate
// hintErr contains an error that may be helpful in determining why an
// authority wasn't found.
hintErr error
// hintCert contains a possible authority certificate that was rejected
// because of the error in hintErr.
hintCert *Certificate
}
func (e UnknownAuthorityError) Error() string {
s := "x509: certificate signed by unknown authority"
if e.hintErr != nil {
certName := e.hintCert.Subject.CommonName
if len(certName) == 0 {
if len(e.hintCert.Subject.Organization) > 0 {
certName = e.hintCert.Subject.Organization[0]
}
certName = "serial:" + e.hintCert.SerialNumber.String()
}
s += fmt.Sprintf(" (possibly because of %q while trying to verify candidate authority certificate %q)", e.hintErr, certName)
}
return s
}
// SystemRootsError results when we fail to load the system root certificates.
type SystemRootsError struct {
}
func (e SystemRootsError) Error() string {
return "x509: failed to load system roots and no roots provided"
}
// VerifyOptions contains parameters for Certificate.Verify. It's a structure
// because other PKIX verification APIs have ended up needing many options.
type VerifyOptions struct {
DNSName string
Intermediates *CertPool
Roots *CertPool // if nil, the system roots are used
CurrentTime time.Time // if zero, the current time is used
DisableTimeChecks bool
// KeyUsage specifies which Extended Key Usage values are acceptable.
// An empty list means ExtKeyUsageServerAuth. Key usage is considered a
// constraint down the chain which mirrors Windows CryptoAPI behaviour,
// but not the spec. To accept any key usage, include ExtKeyUsageAny.
KeyUsages []ExtKeyUsage
}
const (
leafCertificate = iota
intermediateCertificate
rootCertificate
)
// isValid performs validity checks on the c.
func (c *Certificate) isValid(certType int, currentChain []*Certificate, opts *VerifyOptions) error {
if !opts.DisableTimeChecks {
now := opts.CurrentTime
if now.IsZero() {
now = time.Now()
}
if now.Before(c.NotBefore) || now.After(c.NotAfter) {
return CertificateInvalidError{c, Expired}
}
}
if len(c.PermittedDNSDomains) > 0 {
ok := false
for _, domain := range c.PermittedDNSDomains {
if opts.DNSName == domain ||
(strings.HasSuffix(opts.DNSName, domain) &&
len(opts.DNSName) >= 1+len(domain) &&
opts.DNSName[len(opts.DNSName)-len(domain)-1] == '.') {
ok = true
break
}
}
if !ok {
return CertificateInvalidError{c, CANotAuthorizedForThisName}
}
}
// KeyUsage status flags are ignored. From Engineering Security, Peter
// Gutmann: A European government CA marked its signing certificates as
// being valid for encryption only, but no-one noticed. Another
// European CA marked its signature keys as not being valid for
// signatures. A different CA marked its own trusted root certificate
// as being invalid for certificate signing. Another national CA
// distributed a certificate to be used to encrypt data for the
// countrys tax authority that was marked as only being usable for
// digital signatures but not for encryption. Yet another CA reversed
// the order of the bit flags in the keyUsage due to confusion over
// encoding endianness, essentially setting a random keyUsage in
// certificates that it issued. Another CA created a self-invalidating
// certificate by adding a certificate policy statement stipulating
// that the certificate had to be used strictly as specified in the
// keyUsage, and a keyUsage containing a flag indicating that the RSA
// encryption key could only be used for Diffie-Hellman key agreement.
if certType == intermediateCertificate && (!c.BasicConstraintsValid || !c.IsCA) {
return CertificateInvalidError{c, NotAuthorizedToSign}
}
if c.BasicConstraintsValid && c.MaxPathLen >= 0 {
numIntermediates := len(currentChain) - 1
if numIntermediates > c.MaxPathLen {
return CertificateInvalidError{c, TooManyIntermediates}
}
}
return nil
}
// Verify attempts to verify c by building one or more chains from c to a
// certificate in opts.Roots, using certificates in opts.Intermediates if
// needed. If successful, it returns one or more chains where the first
// element of the chain is c and the last element is from opts.Roots.
//
// WARNING: this doesn't do any revocation checking.
func (c *Certificate) Verify(opts VerifyOptions) (chains [][]*Certificate, err error) {
// Use Windows's own verification and chain building.
if opts.Roots == nil && runtime.GOOS == "windows" {
return c.systemVerify(&opts)
}
if opts.Roots == nil {
opts.Roots = systemRootsPool()
if opts.Roots == nil {
return nil, SystemRootsError{}
}
}
err = c.isValid(leafCertificate, nil, &opts)
if err != nil {
return
}
if len(opts.DNSName) > 0 {
err = c.VerifyHostname(opts.DNSName)
if err != nil {
return
}
}
candidateChains, err := c.buildChains(make(map[int][][]*Certificate), []*Certificate{c}, &opts)
if err != nil {
return
}
keyUsages := opts.KeyUsages
if len(keyUsages) == 0 {
keyUsages = []ExtKeyUsage{ExtKeyUsageServerAuth}
}
// If any key usage is acceptable then we're done.
for _, usage := range keyUsages {
if usage == ExtKeyUsageAny {
chains = candidateChains
return
}
}
for _, candidate := range candidateChains {
if checkChainForKeyUsage(candidate, keyUsages) {
chains = append(chains, candidate)
}
}
if len(chains) == 0 {
err = CertificateInvalidError{c, IncompatibleUsage}
}
return
}
func appendToFreshChain(chain []*Certificate, cert *Certificate) []*Certificate {
n := make([]*Certificate, len(chain)+1)
copy(n, chain)
n[len(chain)] = cert
return n
}
func (c *Certificate) buildChains(cache map[int][][]*Certificate, currentChain []*Certificate, opts *VerifyOptions) (chains [][]*Certificate, err error) {
possibleRoots, failedRoot, rootErr := opts.Roots.findVerifiedParents(c)
for _, rootNum := range possibleRoots {
root := opts.Roots.certs[rootNum]
err = root.isValid(rootCertificate, currentChain, opts)
if err != nil {
continue
}
chains = append(chains, appendToFreshChain(currentChain, root))
}
possibleIntermediates, failedIntermediate, intermediateErr := opts.Intermediates.findVerifiedParents(c)
nextIntermediate:
for _, intermediateNum := range possibleIntermediates {
intermediate := opts.Intermediates.certs[intermediateNum]
for _, cert := range currentChain {
if cert == intermediate {
continue nextIntermediate
}
}
err = intermediate.isValid(intermediateCertificate, currentChain, opts)
if err != nil {
continue
}
var childChains [][]*Certificate
childChains, ok := cache[intermediateNum]
if !ok {
childChains, err = intermediate.buildChains(cache, appendToFreshChain(currentChain, intermediate), opts)
cache[intermediateNum] = childChains
}
chains = append(chains, childChains...)
}
if len(chains) > 0 {
err = nil
}
if len(chains) == 0 && err == nil {
hintErr := rootErr
hintCert := failedRoot
if hintErr == nil {
hintErr = intermediateErr
hintCert = failedIntermediate
}
err = UnknownAuthorityError{c, hintErr, hintCert}
}
return
}
func matchHostnames(pattern, host string) bool {
if len(pattern) == 0 || len(host) == 0 {
return false
}
patternParts := strings.Split(pattern, ".")
hostParts := strings.Split(host, ".")
if len(patternParts) != len(hostParts) {
return false
}
for i, patternPart := range patternParts {
if patternPart == "*" {
continue
}
if patternPart != hostParts[i] {
return false
}
}
return true
}
// toLowerCaseASCII returns a lower-case version of in. See RFC 6125 6.4.1. We use
// an explicitly ASCII function to avoid any sharp corners resulting from
// performing Unicode operations on DNS labels.
func toLowerCaseASCII(in string) string {
// If the string is already lower-case then there's nothing to do.
isAlreadyLowerCase := true
for _, c := range in {
if c == utf8.RuneError {
// If we get a UTF-8 error then there might be
// upper-case ASCII bytes in the invalid sequence.
isAlreadyLowerCase = false
break
}
if 'A' <= c && c <= 'Z' {
isAlreadyLowerCase = false
break
}
}
if isAlreadyLowerCase {
return in
}
out := []byte(in)
for i, c := range out {
if 'A' <= c && c <= 'Z' {
out[i] += 'a' - 'A'
}
}
return string(out)
}
// VerifyHostname returns nil if c is a valid certificate for the named host.
// Otherwise it returns an error describing the mismatch.
func (c *Certificate) VerifyHostname(h string) error {
// IP addresses may be written in [ ].
candidateIP := h
if len(h) >= 3 && h[0] == '[' && h[len(h)-1] == ']' {
candidateIP = h[1 : len(h)-1]
}
if ip := net.ParseIP(candidateIP); ip != nil {
// We only match IP addresses against IP SANs.
// https://tools.ietf.org/html/rfc6125#appendix-B.2
for _, candidate := range c.IPAddresses {
if ip.Equal(candidate) {
return nil
}
}
return HostnameError{c, candidateIP}
}
lowered := toLowerCaseASCII(h)
if len(c.DNSNames) > 0 {
for _, match := range c.DNSNames {
if matchHostnames(toLowerCaseASCII(match), lowered) {
return nil
}
}
// If Subject Alt Name is given, we ignore the common name.
} else if matchHostnames(toLowerCaseASCII(c.Subject.CommonName), lowered) {
return nil
}
return HostnameError{c, h}
}
func checkChainForKeyUsage(chain []*Certificate, keyUsages []ExtKeyUsage) bool {
usages := make([]ExtKeyUsage, len(keyUsages))
copy(usages, keyUsages)
if len(chain) == 0 {
return false
}
usagesRemaining := len(usages)
// We walk down the list and cross out any usages that aren't supported
// by each certificate. If we cross out all the usages, then the chain
// is unacceptable.
for i := len(chain) - 1; i >= 0; i-- {
cert := chain[i]
if len(cert.ExtKeyUsage) == 0 && len(cert.UnknownExtKeyUsage) == 0 {
// The certificate doesn't have any extended key usage specified.
continue
}
for _, usage := range cert.ExtKeyUsage {
if usage == ExtKeyUsageAny {
// The certificate is explicitly good for any usage.
continue
}
}
const invalidUsage ExtKeyUsage = -1
NextRequestedUsage:
for i, requestedUsage := range usages {
if requestedUsage == invalidUsage {
continue
}
for _, usage := range cert.ExtKeyUsage {
if requestedUsage == usage {
continue NextRequestedUsage
} else if requestedUsage == ExtKeyUsageServerAuth &&
(usage == ExtKeyUsageNetscapeServerGatedCrypto ||
usage == ExtKeyUsageMicrosoftServerGatedCrypto) {
// In order to support COMODO
// certificate chains, we have to
// accept Netscape or Microsoft SGC
// usages as equal to ServerAuth.
continue NextRequestedUsage
}
}
usages[i] = invalidUsage
usagesRemaining--
if usagesRemaining == 0 {
return false
}
}
}
return true
}

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